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/*-------------------------------------------------------------------------
*
* proclang.c
* PostgreSQL LANGUAGE support code.
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/commands/proclang.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/table.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_language.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/proclang.h"
#include "miscadmin.h"
#include "parser/parse_func.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
/*
* CREATE LANGUAGE
*/
ObjectAddress
CreateProceduralLanguage(CreatePLangStmt *stmt)
{
const char *languageName = stmt->plname;
Oid languageOwner = GetUserId();
Oid handlerOid,
inlineOid,
valOid;
Oid funcrettype;
Oid funcargtypes[1];
Relation rel;
TupleDesc tupDesc;
Datum values[Natts_pg_language];
bool nulls[Natts_pg_language];
bool replaces[Natts_pg_language];
NameData langname;
HeapTuple oldtup;
HeapTuple tup;
Oid langoid;
bool is_update;
ObjectAddress myself,
referenced;
ObjectAddresses *addrs;
/*
* Check permission
*/
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to create custom procedural language")));
/*
* Lookup the PL handler function and check that it is of the expected
* return type
*/
Assert(stmt->plhandler);
handlerOid = LookupFuncName(stmt->plhandler, 0, NULL, false);
funcrettype = get_func_rettype(handlerOid);
if (funcrettype != LANGUAGE_HANDLEROID)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("function %s must return type %s",
NameListToString(stmt->plhandler), "language_handler")));
/* validate the inline function */
if (stmt->plinline)
{
funcargtypes[0] = INTERNALOID;
inlineOid = LookupFuncName(stmt->plinline, 1, funcargtypes, false);
/* return value is ignored, so we don't check the type */
}
else
inlineOid = InvalidOid;
/* validate the validator function */
if (stmt->plvalidator)
{
funcargtypes[0] = OIDOID;
valOid = LookupFuncName(stmt->plvalidator, 1, funcargtypes, false);
/* return value is ignored, so we don't check the type */
}
else
valOid = InvalidOid;
/* ok to create it */
rel = table_open(LanguageRelationId, RowExclusiveLock);
tupDesc = RelationGetDescr(rel);
/* Prepare data to be inserted */
memset(values, 0, sizeof(values));
memset(nulls, false, sizeof(nulls));
memset(replaces, true, sizeof(replaces));
namestrcpy(&langname, languageName);
values[Anum_pg_language_lanname - 1] = NameGetDatum(&langname);
values[Anum_pg_language_lanowner - 1] = ObjectIdGetDatum(languageOwner);
values[Anum_pg_language_lanispl - 1] = BoolGetDatum(true);
values[Anum_pg_language_lanpltrusted - 1] = BoolGetDatum(stmt->pltrusted);
values[Anum_pg_language_lanplcallfoid - 1] = ObjectIdGetDatum(handlerOid);
values[Anum_pg_language_laninline - 1] = ObjectIdGetDatum(inlineOid);
values[Anum_pg_language_lanvalidator - 1] = ObjectIdGetDatum(valOid);
nulls[Anum_pg_language_lanacl - 1] = true;
/* Check for pre-existing definition */
oldtup = SearchSysCache1(LANGNAME, PointerGetDatum(languageName));
if (HeapTupleIsValid(oldtup))
{
Form_pg_language oldform = (Form_pg_language) GETSTRUCT(oldtup);
/* There is one; okay to replace it? */
if (!stmt->replace)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("language \"%s\" already exists", languageName)));
/* This is currently pointless, since we already checked superuser */
#ifdef NOT_USED
if (!pg_language_ownercheck(oldform->oid, languageOwner))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_LANGUAGE,
languageName);
#endif
/*
* Do not change existing oid, ownership or permissions. Note
* dependency-update code below has to agree with this decision.
*/
replaces[Anum_pg_language_oid - 1] = false;
replaces[Anum_pg_language_lanowner - 1] = false;
replaces[Anum_pg_language_lanacl - 1] = false;
/* Okay, do it... */
tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
CatalogTupleUpdate(rel, &tup->t_self, tup);
langoid = oldform->oid;
ReleaseSysCache(oldtup);
is_update = true;
}
else
{
/* Creating a new language */
langoid = GetNewOidWithIndex(rel, LanguageOidIndexId,
Anum_pg_language_oid);
values[Anum_pg_language_oid - 1] = ObjectIdGetDatum(langoid);
tup = heap_form_tuple(tupDesc, values, nulls);
CatalogTupleInsert(rel, tup);
is_update = false;
}
/*
* Create dependencies for the new language. If we are updating an
* existing language, first delete any existing pg_depend entries.
* (However, since we are not changing ownership or permissions, the
* shared dependencies do *not* need to change, and we leave them alone.)
*/
myself.classId = LanguageRelationId;
myself.objectId = langoid;
myself.objectSubId = 0;
if (is_update)
deleteDependencyRecordsFor(myself.classId, myself.objectId, true);
/* dependency on owner of language */
if (!is_update)
recordDependencyOnOwner(myself.classId, myself.objectId,
languageOwner);
/* dependency on extension */
recordDependencyOnCurrentExtension(&myself, is_update);
addrs = new_object_addresses();
/* dependency on the PL handler function */
ObjectAddressSet(referenced, ProcedureRelationId, handlerOid);
add_exact_object_address(&referenced, addrs);
/* dependency on the inline handler function, if any */
if (OidIsValid(inlineOid))
{
ObjectAddressSet(referenced, ProcedureRelationId, inlineOid);
add_exact_object_address(&referenced, addrs);
}
/* dependency on the validator function, if any */
if (OidIsValid(valOid))
{
ObjectAddressSet(referenced, ProcedureRelationId, valOid);
add_exact_object_address(&referenced, addrs);
}
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
free_object_addresses(addrs);
/* Post creation hook for new procedural language */
InvokeObjectPostCreateHook(LanguageRelationId, myself.objectId, 0);
table_close(rel, RowExclusiveLock);
return myself;
}
/*
* get_language_oid - given a language name, look up the OID
*
* If missing_ok is false, throw an error if language name not found. If
* true, just return InvalidOid.
*/
Oid
get_language_oid(const char *langname, bool missing_ok)
{
Oid oid;
oid = GetSysCacheOid1(LANGNAME, Anum_pg_language_oid,
CStringGetDatum(langname));
if (!OidIsValid(oid) && !missing_ok)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("language \"%s\" does not exist", langname)));
return oid;
}
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