functioncmds.c 21.36 KiB
/*-------------------------------------------------------------------------
*
* functioncmds.c
*
* Routines for CREATE and DROP FUNCTION commands
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/functioncmds.c,v 1.15 2002/07/29 23:44:44 tgl Exp $
*
* DESCRIPTION
* These routines take the parse tree and pick out the
* appropriate arguments/flags, and pass the results to the
* corresponding "FooDefine" routines (in src/catalog) that do
* the actual catalog-munging. These routines also verify permission
* of the user to execute the command.
*
* NOTES
* These things must be defined and committed in the following order:
* "create function":
* input/output, recv/send procedures
* "create type":
* type
* "create operator":
* operators
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_cast.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "miscadmin.h"
#include "optimizer/cost.h"
#include "parser/parse_func.h"
#include "parser/parse_type.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
/*
* Examine the "returns" clause returnType 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.
*/
static void
compute_return_type(TypeName *returnType, Oid languageOid,
Oid *prorettype_p, bool *returnsSet_p)
{
Oid rettype;
rettype = LookupTypeName(returnType);
if (OidIsValid(rettype))
{
if (!get_typisdefined(rettype))
{
if (languageOid == SQLlanguageId)
elog(ERROR, "SQL functions cannot return shell types");
else
elog(WARNING, "Return type \"%s\" is only a shell",
TypeNameToString(returnType));
}
}
else
{
char *typnam = TypeNameToString(returnType);
if (strcmp(typnam, "opaque") == 0)
rettype = InvalidOid;
else
{
Oid namespaceId;
AclResult aclresult;
char *typname;
if (languageOid == SQLlanguageId)
elog(ERROR, "Type \"%s\" does not exist", typnam);
elog(WARNING, "ProcedureCreate: type %s is not yet defined",
typnam);
namespaceId = QualifiedNameGetCreationNamespace(returnType->names,
&typname);
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_namespace_name(namespaceId));
rettype = TypeShellMake(typname, namespaceId);
if (!OidIsValid(rettype))
elog(ERROR, "could not create type %s", typnam);
}
}
*prorettype_p = rettype;
*returnsSet_p = returnType->setof;
}
/*
* Interpret the argument-types list of the CREATE FUNCTION statement.
*/
static int
compute_parameter_types(List *argTypes, Oid languageOid,
Oid *parameterTypes)
{
int parameterCount = 0;
List *x;
MemSet(parameterTypes, 0, FUNC_MAX_ARGS * sizeof(Oid));
foreach(x, argTypes)
{
TypeName *t = (TypeName *) lfirst(x);
Oid toid;
if (parameterCount >= FUNC_MAX_ARGS)
elog(ERROR, "functions cannot have more than %d arguments",
FUNC_MAX_ARGS);
toid = LookupTypeName(t);
if (OidIsValid(toid))
{
if (!get_typisdefined(toid)) elog(WARNING, "Argument type \"%s\" is only a shell",
TypeNameToString(t));
}
else
{
char *typnam = TypeNameToString(t);
if (strcmp(typnam, "opaque") == 0)
{
if (languageOid == SQLlanguageId)
elog(ERROR, "SQL functions cannot have arguments of type \"opaque\"");
toid = InvalidOid;
}
else
elog(ERROR, "Type \"%s\" does not exist", typnam);
}
if (t->setof)
elog(ERROR, "functions cannot accept set arguments");
parameterTypes[parameterCount++] = toid;
}
return parameterCount;
}
/*
* Dissect the list of options assembled in gram.y into function
* attributes.
*/
static void
compute_attributes_sql_style(const List *options,
List **as,
char **language,
char *volatility_p,
bool *strict_p,
bool *security_definer)
{
const List *option;
DefElem *as_item = NULL;
DefElem *language_item = NULL;
DefElem *volatility_item = NULL;
DefElem *strict_item = NULL;
DefElem *security_item = NULL;
foreach(option, options)
{
DefElem *defel = (DefElem *) lfirst(option);
if (strcmp(defel->defname, "as")==0)
{
if (as_item)
elog(ERROR, "conflicting or redundant options");
as_item = defel;
}
else if (strcmp(defel->defname, "language")==0)
{
if (language_item)
elog(ERROR, "conflicting or redundant options");
language_item = defel;
}
else if (strcmp(defel->defname, "volatility")==0)
{
if (volatility_item)
elog(ERROR, "conflicting or redundant options");
volatility_item = defel;
}
else if (strcmp(defel->defname, "strict")==0) {
if (strict_item)
elog(ERROR, "conflicting or redundant options");
strict_item = defel;
}
else if (strcmp(defel->defname, "security")==0)
{
if (security_item)
elog(ERROR, "conflicting or redundant options");
security_item = defel;
}
else
elog(ERROR, "invalid CREATE FUNCTION option");
}
if (as_item)
*as = (List *)as_item->arg;
else
elog(ERROR, "no function body specified");
if (language_item)
*language = strVal(language_item->arg);
else
elog(ERROR, "no language specified");
if (volatility_item)
{
if (strcmp(strVal(volatility_item->arg), "immutable")==0)
*volatility_p = PROVOLATILE_IMMUTABLE;
else if (strcmp(strVal(volatility_item->arg), "stable")==0)
*volatility_p = PROVOLATILE_STABLE;
else if (strcmp(strVal(volatility_item->arg), "volatile")==0)
*volatility_p = PROVOLATILE_VOLATILE;
else
elog(ERROR, "invalid volatility");
}
if (strict_item)
*strict_p = intVal(strict_item->arg);
if (security_item)
*security_definer = intVal(security_item->arg);
}
/*-------------
* Interpret the parameters *parameters and return their contents as
* *byte_pct_p, etc.
*
* These parameters supply optional information about a function.
* All have defaults if not specified.
*
* Note: currently, only two of these parameters actually do anything:
*
* * isStrict means the function should not be called when any NULL
* inputs are present; instead a NULL result value should be assumed.
*
* * volatility tells the optimizer whether the function's result can
* be assumed to be repeatable over multiple evaluations.
*
* The other four parameters are not used anywhere. They used to be
* used in the "expensive functions" optimizer, but that's been dead code
* for a long time.
*------------
*/
static void
compute_attributes_with_style(List *parameters, bool *isStrict_p, char *volatility_p)
{
List *pl;
foreach(pl, parameters) {
DefElem *param = (DefElem *) lfirst(pl);
if (strcasecmp(param->defname, "isstrict") == 0)
*isStrict_p = true;
else if (strcasecmp(param->defname, "iscachable") == 0)
{
/* obsolete spelling of isImmutable */
*volatility_p = PROVOLATILE_IMMUTABLE;
}
else
elog(WARNING, "Unrecognized function attribute '%s' ignored",
param->defname);
}
}
/*
* For a dynamically linked C language object, the form of the clause is
*
* AS <object file name> [, <link symbol name> ]
*
* In all other cases
*
* AS <object reference, or sql code>
*
*/
static void
interpret_AS_clause(Oid languageOid, const char *languageName, const List *as,
char **prosrc_str_p, char **probin_str_p)
{
Assert(as != NIL);
if (languageOid == ClanguageId)
{
/*
* For "C" language, store the file name in probin and, when
* given, the link symbol name in prosrc.
*/
*probin_str_p = strVal(lfirst(as));
if (lnext(as) == NULL)
*prosrc_str_p = "-";
else
*prosrc_str_p = strVal(lsecond(as));
}
else
{
/* Everything else wants the given string in prosrc. */
*prosrc_str_p = strVal(lfirst(as));
*probin_str_p = "-";
if (lnext(as) != NIL)
elog(ERROR, "CREATE FUNCTION: only one AS item needed for %s language",
languageName);
}
}
/*
* CreateFunction
* Execute a CREATE FUNCTION utility statement.
*/
void
CreateFunction(CreateFunctionStmt *stmt)
{
char *probin_str;
char *prosrc_str;
Oid prorettype; bool returnsSet;
char *language;
char languageName[NAMEDATALEN];
Oid languageOid;
Oid languageValidator;
char *funcname;
Oid namespaceId;
AclResult aclresult;
int parameterCount;
Oid parameterTypes[FUNC_MAX_ARGS];
bool isStrict,
security;
char volatility;
HeapTuple languageTuple;
Form_pg_language languageStruct;
List *as_clause;
/* Convert list of names to a name and namespace */
namespaceId = QualifiedNameGetCreationNamespace(stmt->funcname,
&funcname);
/* Check we have creation rights in target namespace */
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_namespace_name(namespaceId));
/* defaults attributes */
isStrict = false;
security = false;
volatility = PROVOLATILE_VOLATILE;
/* override attributes from explicit list */
compute_attributes_sql_style(stmt->options,
&as_clause, &language, &volatility, &isStrict, &security);
/* Convert language name to canonical case */
case_translate_language_name(language, languageName);
/* Look up the language and validate permissions */
languageTuple = SearchSysCache(LANGNAME,
PointerGetDatum(languageName),
0, 0, 0);
if (!HeapTupleIsValid(languageTuple))
elog(ERROR, "language \"%s\" does not exist", languageName);
languageOid = HeapTupleGetOid(languageTuple);
languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
if (languageStruct->lanpltrusted)
{
/* if trusted language, need USAGE privilege */
AclResult aclresult;
aclresult = pg_language_aclcheck(languageOid, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, NameStr(languageStruct->lanname));
}
else
{
/* if untrusted language, must be superuser */
if (!superuser())
aclcheck_error(ACLCHECK_NO_PRIV, NameStr(languageStruct->lanname));
}
languageValidator = languageStruct->lanvalidator;
ReleaseSysCache(languageTuple);
/*
* Convert remaining parameters of CREATE to form wanted by * ProcedureCreate.
*/
compute_return_type(stmt->returnType, languageOid,
&prorettype, &returnsSet);
parameterCount = compute_parameter_types(stmt->argTypes, languageOid,
parameterTypes);
compute_attributes_with_style(stmt->withClause, &isStrict, &volatility);
interpret_AS_clause(languageOid, languageName, as_clause,
&prosrc_str, &probin_str);
if (languageOid == INTERNALlanguageId)
{
/*
* In PostgreSQL versions before 6.5, the SQL name of the
* created function could not be different from the internal
* name, and "prosrc" wasn't used. So there is code out there
* that does CREATE FUNCTION xyz AS '' LANGUAGE 'internal'.
* To preserve some modicum of backwards compatibility, accept
* an empty "prosrc" value as meaning the supplied SQL
* function name.
*/
if (strlen(prosrc_str) == 0)
prosrc_str = funcname;
}
if (languageOid == ClanguageId)
{
/* If link symbol is specified as "-", substitute procedure name */
if (strcmp(prosrc_str, "-") == 0)
prosrc_str = funcname;
}
/*
* And now that we have all the parameters, and know we're permitted
* to do so, go ahead and create the function.
*/
ProcedureCreate(funcname,
namespaceId,
stmt->replace,
returnsSet,
prorettype,
languageOid,
languageValidator,
prosrc_str, /* converted to text later */
probin_str, /* converted to text later */
false, /* not an aggregate */
security,
isStrict,
volatility,
parameterCount,
parameterTypes);
}
/*
* RemoveFunction
* Deletes a function.
*/
void
RemoveFunction(RemoveFuncStmt *stmt)
{
List *functionName = stmt->funcname;
List *argTypes = stmt->args; /* list of TypeName nodes */
Oid funcOid;
HeapTuple tup;
ObjectAddress object;
/*
* Find the function, do permissions and validity checks
*/
funcOid = LookupFuncNameTypeNames(functionName, argTypes,
true, "RemoveFunction");
tup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcOid),
0, 0, 0);
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "RemoveFunction: couldn't find tuple for function %s",
NameListToString(functionName));
/* Permission check: must own func or its namespace */
if (!pg_proc_ownercheck(funcOid, GetUserId()) &&
!pg_namespace_ownercheck(((Form_pg_proc) GETSTRUCT(tup))->pronamespace,
GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, NameListToString(functionName));
if (((Form_pg_proc) GETSTRUCT(tup))->proisagg)
elog(ERROR, "RemoveFunction: function '%s' is an aggregate"
"\n\tUse DROP AGGREGATE to remove it",
NameListToString(functionName));
if (((Form_pg_proc) GETSTRUCT(tup))->prolang == INTERNALlanguageId)
{
/* "Helpful" WARNING when removing a builtin function ... */
elog(WARNING, "Removing built-in function \"%s\"",
NameListToString(functionName));
}
ReleaseSysCache(tup);
/*
* Do the deletion
*/
object.classId = RelOid_pg_proc;
object.objectId = funcOid;
object.objectSubId = 0;
performDeletion(&object, stmt->behavior);
}
/*
* Guts of function deletion.
*
* Note: this is also used for aggregate deletion, since the OIDs of
* both functions and aggregates point to pg_proc.
*/
void
RemoveFunctionById(Oid funcOid)
{
Relation relation;
HeapTuple tup;
bool isagg;
/*
* Delete the pg_proc tuple.
*/
relation = heap_openr(ProcedureRelationName, RowExclusiveLock);
tup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcOid),
0, 0, 0);
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "RemoveFunctionById: couldn't find tuple for function %u",
funcOid);
isagg = ((Form_pg_proc) GETSTRUCT(tup))->proisagg;
simple_heap_delete(relation, &tup->t_self);
ReleaseSysCache(tup);
heap_close(relation, RowExclusiveLock);
/*
* If there's a pg_aggregate tuple, delete that too.
*/
if (isagg)
{
relation = heap_openr(AggregateRelationName, RowExclusiveLock);
tup = SearchSysCache(AGGFNOID,
ObjectIdGetDatum(funcOid),
0, 0, 0);
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "RemoveFunctionById: couldn't find pg_aggregate tuple for %u",
funcOid);
simple_heap_delete(relation, &tup->t_self);
ReleaseSysCache(tup);
heap_close(relation, RowExclusiveLock);
}
}
/*
* CREATE CAST
*/
void
CreateCast(CreateCastStmt *stmt)
{
Oid sourcetypeid;
Oid targettypeid;
Oid funcid;
HeapTuple tuple;
Relation relation;
Form_pg_proc procstruct;
Datum values[Natts_pg_proc];
char nulls[Natts_pg_proc];
int i;
ObjectAddress myself,
referenced;
sourcetypeid = LookupTypeName(stmt->sourcetype);
if (!OidIsValid(sourcetypeid))
elog(ERROR, "source data type %s does not exist",
TypeNameToString(stmt->sourcetype));
targettypeid = LookupTypeName(stmt->targettype);
if (!OidIsValid(targettypeid))
elog(ERROR, "target data type %s does not exist",
TypeNameToString(stmt->targettype));
if (sourcetypeid == targettypeid)
elog(ERROR, "source data type and target data type are the same");
relation = heap_openr(CastRelationName, RowExclusiveLock);
tuple = SearchSysCache(CASTSOURCETARGET,
ObjectIdGetDatum(sourcetypeid),
ObjectIdGetDatum(targettypeid),
0, 0);
if (HeapTupleIsValid(tuple)) elog(ERROR, "cast from data type %s to data type %s already exists",
TypeNameToString(stmt->sourcetype),
TypeNameToString(stmt->targettype));
if (stmt->func != NULL)
{
funcid = LookupFuncNameTypeNames(stmt->func->funcname,
stmt->func->funcargs,
false,
"CreateCast");
if (!pg_proc_ownercheck(funcid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
NameListToString(stmt->func->funcname));
tuple = SearchSysCache(PROCOID, ObjectIdGetDatum(funcid), 0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup of function %u failed", funcid);
procstruct = (Form_pg_proc) GETSTRUCT(tuple);
if (procstruct->pronargs != 1)
elog(ERROR, "cast function must take 1 argument");
if (procstruct->proargtypes[0] != sourcetypeid)
elog(ERROR, "argument of cast function must match source data type");
if (procstruct->prorettype != targettypeid)
elog(ERROR, "return data type of cast function must match target data type");
if (procstruct->provolatile != PROVOLATILE_IMMUTABLE)
elog(ERROR, "cast function must be immutable");
if (procstruct->proisagg)
elog(ERROR, "cast function must not be an aggregate function");
if (procstruct->proretset)
elog(ERROR, "cast function must not return a set");
ReleaseSysCache(tuple);
}
else
{
/* indicates binary compatibility */
if (!pg_type_ownercheck(sourcetypeid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
TypeNameToString(stmt->sourcetype));
if (!pg_type_ownercheck(targettypeid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
TypeNameToString(stmt->targettype));
funcid = InvalidOid;
}
/* ready to go */
values[Anum_pg_cast_castsource-1] = ObjectIdGetDatum(sourcetypeid);
values[Anum_pg_cast_casttarget-1] = ObjectIdGetDatum(targettypeid);
values[Anum_pg_cast_castfunc-1] = ObjectIdGetDatum(funcid);
values[Anum_pg_cast_castimplicit-1] = BoolGetDatum(stmt->implicit);
for (i = 0; i < Natts_pg_cast; ++i)
nulls[i] = ' ';
tuple = heap_formtuple(RelationGetDescr(relation), values, nulls);
simple_heap_insert(relation, tuple);
if (RelationGetForm(relation)->relhasindex)
{
Relation idescs[Num_pg_cast_indices];
CatalogOpenIndices(Num_pg_cast_indices, Name_pg_cast_indices, idescs);
CatalogIndexInsert(idescs, Num_pg_cast_indices, relation, tuple);
CatalogCloseIndices(Num_pg_cast_indices, idescs);
}
myself.classId = RelationGetRelid(relation);
myself.objectId = HeapTupleGetOid(tuple); myself.objectSubId = 0;
/* dependency on source type */
referenced.classId = RelOid_pg_type;
referenced.objectId = sourcetypeid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* dependency on target type */
referenced.classId = RelOid_pg_type;
referenced.objectId = targettypeid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
/* dependency on function */
if (OidIsValid(funcid))
{
referenced.classId = RelOid_pg_proc;
referenced.objectId = funcid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
heap_freetuple(tuple);
heap_close(relation, RowExclusiveLock);
}
/*
* DROP CAST
*/
void
DropCast(DropCastStmt *stmt)
{
Oid sourcetypeid;
Oid targettypeid;
HeapTuple tuple;
Form_pg_cast caststruct;
ObjectAddress object;
sourcetypeid = LookupTypeName(stmt->sourcetype);
if (!OidIsValid(sourcetypeid))
elog(ERROR, "source data type %s does not exist",
TypeNameToString(stmt->sourcetype));
targettypeid = LookupTypeName(stmt->targettype);
if (!OidIsValid(targettypeid))
elog(ERROR, "target data type %s does not exist",
TypeNameToString(stmt->targettype));
tuple = SearchSysCache(CASTSOURCETARGET,
ObjectIdGetDatum(sourcetypeid),
ObjectIdGetDatum(targettypeid),
0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cast from type %s to type %s does not exist",
TypeNameToString(stmt->sourcetype),
TypeNameToString(stmt->targettype));
/* Permission check */
caststruct = (Form_pg_cast) GETSTRUCT(tuple);
if (caststruct->castfunc != InvalidOid)
{
if (!pg_proc_ownercheck(caststruct->castfunc, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
get_func_name(caststruct->castfunc));
}
else
{ if (!pg_type_ownercheck(sourcetypeid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
format_type_be(sourcetypeid));
if (!pg_type_ownercheck(targettypeid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER,
format_type_be(targettypeid));
}
/*
* Do the deletion
*/
object.classId = get_system_catalog_relid(CastRelationName);
object.objectId = HeapTupleGetOid(tuple);
object.objectSubId = 0;
ReleaseSysCache(tuple);
performDeletion(&object, stmt->behavior);
}
void
DropCastById(Oid castOid)
{
Relation relation,
index;
ScanKeyData scankey;
IndexScanDesc scan;
HeapTuple tuple;
relation = heap_openr(CastRelationName, RowExclusiveLock);
index = index_openr(CastOidIndex);
ScanKeyEntryInitialize(&scankey, 0x0,
1, F_OIDEQ, ObjectIdGetDatum(castOid));
scan = index_beginscan(relation, index, SnapshotNow, 1, &scankey);
tuple = index_getnext(scan, ForwardScanDirection);
if (HeapTupleIsValid(tuple))
simple_heap_delete(relation, &tuple->t_self);
else
elog(ERROR, "could not find tuple for cast %u", castOid);
index_endscan(scan);
index_close(index);
heap_close(relation, RowExclusiveLock);
}