/*-------------------------------------------------------------------------
 *
 * aclchk.c
 *	  Routines to check access control permissions.
 *
 * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  src/backend/catalog/aclchk.c
 *
 * NOTES
 *	  See acl.h.
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/genam.h"
#include "access/heapam.h"
#include "access/sysattr.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_conversion.h"
#include "catalog/pg_database.h"
#include "catalog/pg_default_acl.h"
#include "catalog/pg_extension.h"
#include "catalog/pg_foreign_data_wrapper.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_language.h"
#include "catalog/pg_largeobject.h"
#include "catalog/pg_largeobject_metadata.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
#include "catalog/pg_ts_config.h"
#include "catalog/pg_ts_dict.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
#include "foreign/foreign.h"
#include "miscadmin.h"
#include "parser/parse_func.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
#include "utils/tqual.h"


/*
 * The information about one Grant/Revoke statement, in internal format: object
 * and grantees names have been turned into Oids, the privilege list is an
 * AclMode bitmask.  If 'privileges' is ACL_NO_RIGHTS (the 0 value) and
 * all_privs is true, 'privileges' will be internally set to the right kind of
 * ACL_ALL_RIGHTS_*, depending on the object type (NB - this will modify the
 * InternalGrant struct!)
 *
 * Note: 'all_privs' and 'privileges' represent object-level privileges only.
 * There might also be column-level privilege specifications, which are
 * represented in col_privs (this is a list of untransformed AccessPriv nodes).
 * Column privileges are only valid for objtype ACL_OBJECT_RELATION.
 */
typedef struct
{
	bool		is_grant;
	GrantObjectType objtype;
	List	   *objects;
	bool		all_privs;
	AclMode		privileges;
	List	   *col_privs;
	List	   *grantees;
	bool		grant_option;
	DropBehavior behavior;
} InternalGrant;

/*
 * Internal format used by ALTER DEFAULT PRIVILEGES.
 */
typedef struct
{
	Oid			roleid;			/* owning role */
	Oid			nspid;			/* namespace, or InvalidOid if none */
	/* remaining fields are same as in InternalGrant: */
	bool		is_grant;
	GrantObjectType objtype;
	bool		all_privs;
	AclMode		privileges;
	List	   *grantees;
	bool		grant_option;
	DropBehavior behavior;
} InternalDefaultACL;


static void ExecGrantStmt_oids(InternalGrant *istmt);
static void ExecGrant_Relation(InternalGrant *grantStmt);
static void ExecGrant_Database(InternalGrant *grantStmt);
static void ExecGrant_Fdw(InternalGrant *grantStmt);
static void ExecGrant_ForeignServer(InternalGrant *grantStmt);
static void ExecGrant_Function(InternalGrant *grantStmt);
static void ExecGrant_Language(InternalGrant *grantStmt);
static void ExecGrant_Largeobject(InternalGrant *grantStmt);
static void ExecGrant_Namespace(InternalGrant *grantStmt);
static void ExecGrant_Tablespace(InternalGrant *grantStmt);

static void SetDefaultACLsInSchemas(InternalDefaultACL *iacls, List *nspnames);
static void SetDefaultACL(InternalDefaultACL *iacls);

static List *objectNamesToOids(GrantObjectType objtype, List *objnames);
static List *objectsInSchemaToOids(GrantObjectType objtype, List *nspnames);
static List *getRelationsInNamespace(Oid namespaceId, char relkind);
static void expand_col_privileges(List *colnames, Oid table_oid,
					  AclMode this_privileges,
					  AclMode *col_privileges,
					  int num_col_privileges);
static void expand_all_col_privileges(Oid table_oid, Form_pg_class classForm,
						  AclMode this_privileges,
						  AclMode *col_privileges,
						  int num_col_privileges);
static AclMode string_to_privilege(const char *privname);
static const char *privilege_to_string(AclMode privilege);
static AclMode restrict_and_check_grant(bool is_grant, AclMode avail_goptions,
						 bool all_privs, AclMode privileges,
						 Oid objectId, Oid grantorId,
						 AclObjectKind objkind, const char *objname,
						 AttrNumber att_number, const char *colname);
static AclMode pg_aclmask(AclObjectKind objkind, Oid table_oid, AttrNumber attnum,
		   Oid roleid, AclMode mask, AclMaskHow how);


#ifdef ACLDEBUG
static void
dumpacl(Acl *acl)
{
	int			i;
	AclItem    *aip;

	elog(DEBUG2, "acl size = %d, # acls = %d",
		 ACL_SIZE(acl), ACL_NUM(acl));
	aip = ACL_DAT(acl);
	for (i = 0; i < ACL_NUM(acl); ++i)
		elog(DEBUG2, "	acl[%d]: %s", i,
			 DatumGetCString(DirectFunctionCall1(aclitemout,
												 PointerGetDatum(aip + i))));
}
#endif   /* ACLDEBUG */


/*
 * If is_grant is true, adds the given privileges for the list of
 * grantees to the existing old_acl.  If is_grant is false, the
 * privileges for the given grantees are removed from old_acl.
 *
 * NB: the original old_acl is pfree'd.
 */
static Acl *
merge_acl_with_grant(Acl *old_acl, bool is_grant,
					 bool grant_option, DropBehavior behavior,
					 List *grantees, AclMode privileges,
					 Oid grantorId, Oid ownerId)
{
	unsigned	modechg;
	ListCell   *j;
	Acl		   *new_acl;

	modechg = is_grant ? ACL_MODECHG_ADD : ACL_MODECHG_DEL;

#ifdef ACLDEBUG
	dumpacl(old_acl);
#endif
	new_acl = old_acl;

	foreach(j, grantees)
	{
		AclItem aclitem;
		Acl		   *newer_acl;

		aclitem.	ai_grantee = lfirst_oid(j);

		/*
		 * Grant options can only be granted to individual roles, not PUBLIC.
		 * The reason is that if a user would re-grant a privilege that he
		 * held through PUBLIC, and later the user is removed, the situation
		 * is impossible to clean up.
		 */
		if (is_grant && grant_option && aclitem.ai_grantee == ACL_ID_PUBLIC)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_GRANT_OPERATION),
					 errmsg("grant options can only be granted to roles")));

		aclitem.	ai_grantor = grantorId;

		/*
		 * The asymmetry in the conditions here comes from the spec.  In
		 * GRANT, the grant_option flag signals WITH GRANT OPTION, which means
		 * to grant both the basic privilege and its grant option. But in
		 * REVOKE, plain revoke revokes both the basic privilege and its grant
		 * option, while REVOKE GRANT OPTION revokes only the option.
		 */
		ACLITEM_SET_PRIVS_GOPTIONS(aclitem,
					(is_grant || !grant_option) ? privileges : ACL_NO_RIGHTS,
				   (!is_grant || grant_option) ? privileges : ACL_NO_RIGHTS);

		newer_acl = aclupdate(new_acl, &aclitem, modechg, ownerId, behavior);

		/* avoid memory leak when there are many grantees */
		pfree(new_acl);
		new_acl = newer_acl;

#ifdef ACLDEBUG
		dumpacl(new_acl);
#endif
	}

	return new_acl;
}

/*
 * Restrict the privileges to what we can actually grant, and emit
 * the standards-mandated warning and error messages.
 */
static AclMode
restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
						 AclMode privileges, Oid objectId, Oid grantorId,
						 AclObjectKind objkind, const char *objname,
						 AttrNumber att_number, const char *colname)
{
	AclMode		this_privileges;
	AclMode		whole_mask;

	switch (objkind)
	{
		case ACL_KIND_COLUMN:
			whole_mask = ACL_ALL_RIGHTS_COLUMN;
			break;
		case ACL_KIND_CLASS:
			whole_mask = ACL_ALL_RIGHTS_RELATION;
			break;
		case ACL_KIND_SEQUENCE:
			whole_mask = ACL_ALL_RIGHTS_SEQUENCE;
			break;
		case ACL_KIND_DATABASE:
			whole_mask = ACL_ALL_RIGHTS_DATABASE;
			break;
		case ACL_KIND_PROC:
			whole_mask = ACL_ALL_RIGHTS_FUNCTION;
			break;
		case ACL_KIND_LANGUAGE:
			whole_mask = ACL_ALL_RIGHTS_LANGUAGE;
			break;
		case ACL_KIND_LARGEOBJECT:
			whole_mask = ACL_ALL_RIGHTS_LARGEOBJECT;
			break;
		case ACL_KIND_NAMESPACE:
			whole_mask = ACL_ALL_RIGHTS_NAMESPACE;
			break;
		case ACL_KIND_TABLESPACE:
			whole_mask = ACL_ALL_RIGHTS_TABLESPACE;
			break;
		case ACL_KIND_FDW:
			whole_mask = ACL_ALL_RIGHTS_FDW;
			break;
		case ACL_KIND_FOREIGN_SERVER:
			whole_mask = ACL_ALL_RIGHTS_FOREIGN_SERVER;
			break;
		default:
			elog(ERROR, "unrecognized object kind: %d", objkind);
			/* not reached, but keep compiler quiet */
			return ACL_NO_RIGHTS;
	}

	/*
	 * If we found no grant options, consider whether to issue a hard error.
	 * Per spec, having any privilege at all on the object will get you by
	 * here.
	 */
	if (avail_goptions == ACL_NO_RIGHTS)
	{
		if (pg_aclmask(objkind, objectId, att_number, grantorId,
					   whole_mask | ACL_GRANT_OPTION_FOR(whole_mask),
					   ACLMASK_ANY) == ACL_NO_RIGHTS)
		{
			if (objkind == ACL_KIND_COLUMN && colname)
				aclcheck_error_col(ACLCHECK_NO_PRIV, objkind, objname, colname);
			else
				aclcheck_error(ACLCHECK_NO_PRIV, objkind, objname);
		}
	}

	/*
	 * Restrict the operation to what we can actually grant or revoke, and
	 * issue a warning if appropriate.	(For REVOKE this isn't quite what the
	 * spec says to do: the spec seems to want a warning only if no privilege
	 * bits actually change in the ACL. In practice that behavior seems much
	 * too noisy, as well as inconsistent with the GRANT case.)
	 */
	this_privileges = privileges & ACL_OPTION_TO_PRIVS(avail_goptions);
	if (is_grant)
	{
		if (this_privileges == 0)
		{
			if (objkind == ACL_KIND_COLUMN && colname)
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_GRANTED),
						 errmsg("no privileges were granted for column \"%s\" of relation \"%s\"",
								colname, objname)));
			else
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_GRANTED),
						 errmsg("no privileges were granted for \"%s\"",
								objname)));
		}
		else if (!all_privs && this_privileges != privileges)
		{
			if (objkind == ACL_KIND_COLUMN && colname)
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_GRANTED),
						 errmsg("not all privileges were granted for column \"%s\" of relation \"%s\"",
								colname, objname)));
			else
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_GRANTED),
						 errmsg("not all privileges were granted for \"%s\"",
								objname)));
		}
	}
	else
	{
		if (this_privileges == 0)
		{
			if (objkind == ACL_KIND_COLUMN && colname)
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_REVOKED),
						 errmsg("no privileges could be revoked for column \"%s\" of relation \"%s\"",
								colname, objname)));
			else
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_REVOKED),
						 errmsg("no privileges could be revoked for \"%s\"",
								objname)));
		}
		else if (!all_privs && this_privileges != privileges)
		{
			if (objkind == ACL_KIND_COLUMN && colname)
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_REVOKED),
						 errmsg("not all privileges could be revoked for column \"%s\" of relation \"%s\"",
								colname, objname)));
			else
				ereport(WARNING,
						(errcode(ERRCODE_WARNING_PRIVILEGE_NOT_REVOKED),
					 errmsg("not all privileges could be revoked for \"%s\"",
							objname)));
		}
	}

	return this_privileges;
}

/*
 * Called to execute the utility commands GRANT and REVOKE
 */
void
ExecuteGrantStmt(GrantStmt *stmt)
{
	InternalGrant istmt;
	ListCell   *cell;
	const char *errormsg;
	AclMode		all_privileges;

	/*
	 * Turn the regular GrantStmt into the InternalGrant form.
	 */
	istmt.is_grant = stmt->is_grant;
	istmt.objtype = stmt->objtype;

	/* Collect the OIDs of the target objects */
	switch (stmt->targtype)
	{
		case ACL_TARGET_OBJECT:
			istmt.objects = objectNamesToOids(stmt->objtype, stmt->objects);
			break;
		case ACL_TARGET_ALL_IN_SCHEMA:
			istmt.objects = objectsInSchemaToOids(stmt->objtype, stmt->objects);
			break;
			/* ACL_TARGET_DEFAULTS should not be seen here */
		default:
			elog(ERROR, "unrecognized GrantStmt.targtype: %d",
				 (int) stmt->targtype);
	}

	/* all_privs to be filled below */
	/* privileges to be filled below */
	istmt.col_privs = NIL;		/* may get filled below */
	istmt.grantees = NIL;		/* filled below */
	istmt.grant_option = stmt->grant_option;
	istmt.behavior = stmt->behavior;

	/*
	 * Convert the PrivGrantee list into an Oid list.  Note that at this point
	 * we insert an ACL_ID_PUBLIC into the list if an empty role name is
	 * detected (which is what the grammar uses if PUBLIC is found), so
	 * downstream there shouldn't be any additional work needed to support
	 * this case.
	 */
	foreach(cell, stmt->grantees)
	{
		PrivGrantee *grantee = (PrivGrantee *) lfirst(cell);

		if (grantee->rolname == NULL)
			istmt.grantees = lappend_oid(istmt.grantees, ACL_ID_PUBLIC);
		else
			istmt.grantees =
				lappend_oid(istmt.grantees,
							get_role_oid(grantee->rolname, false));
	}

	/*
	 * Convert stmt->privileges, a list of AccessPriv nodes, into an AclMode
	 * bitmask.  Note: objtype can't be ACL_OBJECT_COLUMN.
	 */
	switch (stmt->objtype)
	{
			/*
			 * Because this might be a sequence, we test both relation and
			 * sequence bits, and later do a more limited test when we know
			 * the object type.
			 */
		case ACL_OBJECT_RELATION:
			all_privileges = ACL_ALL_RIGHTS_RELATION | ACL_ALL_RIGHTS_SEQUENCE;
			errormsg = gettext_noop("invalid privilege type %s for relation");
			break;
		case ACL_OBJECT_SEQUENCE:
			all_privileges = ACL_ALL_RIGHTS_SEQUENCE;
			errormsg = gettext_noop("invalid privilege type %s for sequence");
			break;
		case ACL_OBJECT_DATABASE:
			all_privileges = ACL_ALL_RIGHTS_DATABASE;
			errormsg = gettext_noop("invalid privilege type %s for database");
			break;
		case ACL_OBJECT_FUNCTION:
			all_privileges = ACL_ALL_RIGHTS_FUNCTION;
			errormsg = gettext_noop("invalid privilege type %s for function");
			break;
		case ACL_OBJECT_LANGUAGE:
			all_privileges = ACL_ALL_RIGHTS_LANGUAGE;
			errormsg = gettext_noop("invalid privilege type %s for language");
			break;
		case ACL_OBJECT_LARGEOBJECT:
			all_privileges = ACL_ALL_RIGHTS_LARGEOBJECT;
			errormsg = gettext_noop("invalid privilege type %s for large object");
			break;
		case ACL_OBJECT_NAMESPACE:
			all_privileges = ACL_ALL_RIGHTS_NAMESPACE;
			errormsg = gettext_noop("invalid privilege type %s for schema");
			break;
		case ACL_OBJECT_TABLESPACE:
			all_privileges = ACL_ALL_RIGHTS_TABLESPACE;
			errormsg = gettext_noop("invalid privilege type %s for tablespace");
			break;
		case ACL_OBJECT_FDW:
			all_privileges = ACL_ALL_RIGHTS_FDW;
			errormsg = gettext_noop("invalid privilege type %s for foreign-data wrapper");
			break;
		case ACL_OBJECT_FOREIGN_SERVER:
			all_privileges = ACL_ALL_RIGHTS_FOREIGN_SERVER;
			errormsg = gettext_noop("invalid privilege type %s for foreign server");
			break;
		default:
			elog(ERROR, "unrecognized GrantStmt.objtype: %d",
				 (int) stmt->objtype);
			/* keep compiler quiet */
			all_privileges = ACL_NO_RIGHTS;
			errormsg = NULL;
	}

	if (stmt->privileges == NIL)
	{
		istmt.all_privs = true;

		/*
		 * will be turned into ACL_ALL_RIGHTS_* by the internal routines
		 * depending on the object type
		 */
		istmt.privileges = ACL_NO_RIGHTS;
	}
	else
	{
		istmt.all_privs = false;
		istmt.privileges = ACL_NO_RIGHTS;

		foreach(cell, stmt->privileges)
		{
			AccessPriv *privnode = (AccessPriv *) lfirst(cell);
			AclMode		priv;

			/*
			 * If it's a column-level specification, we just set it aside in
			 * col_privs for the moment; but insist it's for a relation.
			 */
			if (privnode->cols)
			{
				if (stmt->objtype != ACL_OBJECT_RELATION)
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_GRANT_OPERATION),
							 errmsg("column privileges are only valid for relations")));
				istmt.col_privs = lappend(istmt.col_privs, privnode);
				continue;
			}

			if (privnode->priv_name == NULL)	/* parser mistake? */
				elog(ERROR, "AccessPriv node must specify privilege or columns");
			priv = string_to_privilege(privnode->priv_name);

			if (priv & ~((AclMode) all_privileges))
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_GRANT_OPERATION),
						 errmsg(errormsg, privilege_to_string(priv))));

			istmt.privileges |= priv;
		}
	}

	ExecGrantStmt_oids(&istmt);
}

/*
 * ExecGrantStmt_oids
 *
 * Internal entry point for granting and revoking privileges.
 */
static void
ExecGrantStmt_oids(InternalGrant *istmt)
{
	switch (istmt->objtype)
	{
		case ACL_OBJECT_RELATION:
		case ACL_OBJECT_SEQUENCE:
			ExecGrant_Relation(istmt);
			break;
		case ACL_OBJECT_DATABASE:
			ExecGrant_Database(istmt);
			break;
		case ACL_OBJECT_FDW:
			ExecGrant_Fdw(istmt);
			break;
		case ACL_OBJECT_FOREIGN_SERVER:
			ExecGrant_ForeignServer(istmt);
			break;
		case ACL_OBJECT_FUNCTION:
			ExecGrant_Function(istmt);
			break;
		case ACL_OBJECT_LANGUAGE:
			ExecGrant_Language(istmt);
			break;
		case ACL_OBJECT_LARGEOBJECT:
			ExecGrant_Largeobject(istmt);
			break;
		case ACL_OBJECT_NAMESPACE:
			ExecGrant_Namespace(istmt);
			break;
		case ACL_OBJECT_TABLESPACE:
			ExecGrant_Tablespace(istmt);
			break;
		default:
			elog(ERROR, "unrecognized GrantStmt.objtype: %d",
				 (int) istmt->objtype);
	}
}

/*
 * objectNamesToOids
 *
 * Turn a list of object names of a given type into an Oid list.
 */
static List *
objectNamesToOids(GrantObjectType objtype, List *objnames)
{
	List	   *objects = NIL;
	ListCell   *cell;

	Assert(objnames != NIL);

	switch (objtype)
	{
		case ACL_OBJECT_RELATION:
		case ACL_OBJECT_SEQUENCE:
			foreach(cell, objnames)
			{
				RangeVar   *relvar = (RangeVar *) lfirst(cell);
				Oid			relOid;

				relOid = RangeVarGetRelid(relvar, false);
				objects = lappend_oid(objects, relOid);
			}
			break;
		case ACL_OBJECT_DATABASE:
			foreach(cell, objnames)
			{
				char	   *dbname = strVal(lfirst(cell));
				Oid			dbid;

				dbid = get_database_oid(dbname, false);
				objects = lappend_oid(objects, dbid);
			}
			break;
		case ACL_OBJECT_FUNCTION:
			foreach(cell, objnames)
			{
				FuncWithArgs *func = (FuncWithArgs *) lfirst(cell);
				Oid			funcid;

				funcid = LookupFuncNameTypeNames(func->funcname,
												 func->funcargs, false);
				objects = lappend_oid(objects, funcid);
			}
			break;
		case ACL_OBJECT_LANGUAGE:
			foreach(cell, objnames)
			{
				char	   *langname = strVal(lfirst(cell));
				Oid			oid;

				oid = get_language_oid(langname, false);
				objects = lappend_oid(objects, oid);
			}
			break;
		case ACL_OBJECT_LARGEOBJECT:
			foreach(cell, objnames)
			{
				Oid			lobjOid = oidparse(lfirst(cell));

				if (!LargeObjectExists(lobjOid))
					ereport(ERROR,
							(errcode(ERRCODE_UNDEFINED_OBJECT),
							 errmsg("large object %u does not exist",
									lobjOid)));

				objects = lappend_oid(objects, lobjOid);
			}
			break;
		case ACL_OBJECT_NAMESPACE:
			foreach(cell, objnames)
			{
				char	   *nspname = strVal(lfirst(cell));
				Oid			oid;

				oid = get_namespace_oid(nspname, false);
				objects = lappend_oid(objects, oid);
			}
			break;
		case ACL_OBJECT_TABLESPACE:
			foreach(cell, objnames)
			{
				char	   *spcname = strVal(lfirst(cell));
				Oid			spcoid;

				spcoid = get_tablespace_oid(spcname, false);
				objects = lappend_oid(objects, spcoid);
			}
			break;
		case ACL_OBJECT_FDW:
			foreach(cell, objnames)
			{
				char	   *fdwname = strVal(lfirst(cell));
				Oid			fdwid = get_foreign_data_wrapper_oid(fdwname, false);

				objects = lappend_oid(objects, fdwid);
			}
			break;
		case ACL_OBJECT_FOREIGN_SERVER:
			foreach(cell, objnames)
			{
				char	   *srvname = strVal(lfirst(cell));
				Oid			srvid = get_foreign_server_oid(srvname, false);

				objects = lappend_oid(objects, srvid);
			}
			break;
		default:
			elog(ERROR, "unrecognized GrantStmt.objtype: %d",
				 (int) objtype);
	}

	return objects;
}

/*
 * objectsInSchemaToOids
 *
 * Find all objects of a given type in specified schemas, and make a list
 * of their Oids.  We check USAGE privilege on the schemas, but there is
 * no privilege checking on the individual objects here.
 */
static List *
objectsInSchemaToOids(GrantObjectType objtype, List *nspnames)
{
	List	   *objects = NIL;
	ListCell   *cell;

	foreach(cell, nspnames)
	{
		char	   *nspname = strVal(lfirst(cell));
		Oid			namespaceId;
		List	   *objs;

		namespaceId = LookupExplicitNamespace(nspname);

		switch (objtype)
		{
			case ACL_OBJECT_RELATION:
				/* Process regular tables, views and foreign tables */
				objs = getRelationsInNamespace(namespaceId, RELKIND_RELATION);
				objects = list_concat(objects, objs);
				objs = getRelationsInNamespace(namespaceId, RELKIND_VIEW);
				objects = list_concat(objects, objs);
				objs = getRelationsInNamespace(namespaceId, RELKIND_FOREIGN_TABLE);
				objects = list_concat(objects, objs);
				break;
			case ACL_OBJECT_SEQUENCE:
				objs = getRelationsInNamespace(namespaceId, RELKIND_SEQUENCE);
				objects = list_concat(objects, objs);
				break;
			case ACL_OBJECT_FUNCTION:
				{
					ScanKeyData key[1];
					Relation	rel;
					HeapScanDesc scan;
					HeapTuple	tuple;

					ScanKeyInit(&key[0],
								Anum_pg_proc_pronamespace,
								BTEqualStrategyNumber, F_OIDEQ,
								ObjectIdGetDatum(namespaceId));

					rel = heap_open(ProcedureRelationId, AccessShareLock);
					scan = heap_beginscan(rel, SnapshotNow, 1, key);

					while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
					{
						objects = lappend_oid(objects, HeapTupleGetOid(tuple));
					}

					heap_endscan(scan);
					heap_close(rel, AccessShareLock);
				}
				break;
			default:
				/* should not happen */
				elog(ERROR, "unrecognized GrantStmt.objtype: %d",
					 (int) objtype);
		}
	}

	return objects;
}

/*
 * getRelationsInNamespace
 *
 * Return Oid list of relations in given namespace filtered by relation kind
 */
static List *
getRelationsInNamespace(Oid namespaceId, char relkind)
{
	List	   *relations = NIL;
	ScanKeyData key[2];
	Relation	rel;
	HeapScanDesc scan;
	HeapTuple	tuple;

	ScanKeyInit(&key[0],
				Anum_pg_class_relnamespace,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(namespaceId));
	ScanKeyInit(&key[1],
				Anum_pg_class_relkind,
				BTEqualStrategyNumber, F_CHAREQ,
				CharGetDatum(relkind));

	rel = heap_open(RelationRelationId, AccessShareLock);
	scan = heap_beginscan(rel, SnapshotNow, 2, key);

	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
	{
		relations = lappend_oid(relations, HeapTupleGetOid(tuple));
	}

	heap_endscan(scan);
	heap_close(rel, AccessShareLock);

	return relations;
}


/*
 * ALTER DEFAULT PRIVILEGES statement
 */
void
ExecAlterDefaultPrivilegesStmt(AlterDefaultPrivilegesStmt *stmt)
{
	GrantStmt  *action = stmt->action;
	InternalDefaultACL iacls;
	ListCell   *cell;
	List	   *rolenames = NIL;
	List	   *nspnames = NIL;
	DefElem    *drolenames = NULL;
	DefElem    *dnspnames = NULL;
	AclMode		all_privileges;
	const char *errormsg;

	/* Deconstruct the "options" part of the statement */
	foreach(cell, stmt->options)
	{
		DefElem    *defel = (DefElem *) lfirst(cell);

		if (strcmp(defel->defname, "schemas") == 0)
		{
			if (dnspnames)
				ereport(ERROR,
						(errcode(ERRCODE_SYNTAX_ERROR),
						 errmsg("conflicting or redundant options")));
			dnspnames = defel;
		}
		else if (strcmp(defel->defname, "roles") == 0)
		{
			if (drolenames)
				ereport(ERROR,
						(errcode(ERRCODE_SYNTAX_ERROR),
						 errmsg("conflicting or redundant options")));
			drolenames = defel;
		}
		else
			elog(ERROR, "option \"%s\" not recognized", defel->defname);
	}

	if (dnspnames)
		nspnames = (List *) dnspnames->arg;
	if (drolenames)
		rolenames = (List *) drolenames->arg;

	/* Prepare the InternalDefaultACL representation of the statement */
	/* roleid to be filled below */
	/* nspid to be filled in SetDefaultACLsInSchemas */
	iacls.is_grant = action->is_grant;
	iacls.objtype = action->objtype;
	/* all_privs to be filled below */
	/* privileges to be filled below */
	iacls.grantees = NIL;		/* filled below */
	iacls.grant_option = action->grant_option;
	iacls.behavior = action->behavior;

	/*
	 * Convert the PrivGrantee list into an Oid list.  Note that at this point
	 * we insert an ACL_ID_PUBLIC into the list if an empty role name is
	 * detected (which is what the grammar uses if PUBLIC is found), so
	 * downstream there shouldn't be any additional work needed to support
	 * this case.
	 */
	foreach(cell, action->grantees)
	{
		PrivGrantee *grantee = (PrivGrantee *) lfirst(cell);

		if (grantee->rolname == NULL)
			iacls.grantees = lappend_oid(iacls.grantees, ACL_ID_PUBLIC);
		else
			iacls.grantees =
				lappend_oid(iacls.grantees,
							get_role_oid(grantee->rolname, false));
	}

	/*
	 * Convert action->privileges, a list of privilege strings, into an
	 * AclMode bitmask.
	 */
	switch (action->objtype)
	{
		case ACL_OBJECT_RELATION:
			all_privileges = ACL_ALL_RIGHTS_RELATION;
			errormsg = gettext_noop("invalid privilege type %s for relation");
			break;
		case ACL_OBJECT_SEQUENCE:
			all_privileges = ACL_ALL_RIGHTS_SEQUENCE;
			errormsg = gettext_noop("invalid privilege type %s for sequence");
			break;
		case ACL_OBJECT_FUNCTION:
			all_privileges = ACL_ALL_RIGHTS_FUNCTION;
			errormsg = gettext_noop("invalid privilege type %s for function");
			break;
		default:
			elog(ERROR, "unrecognized GrantStmt.objtype: %d",
				 (int) action->objtype);
			/* keep compiler quiet */
			all_privileges = ACL_NO_RIGHTS;
			errormsg = NULL;
	}

	if (action->privileges == NIL)
	{
		iacls.all_privs = true;

		/*
		 * will be turned into ACL_ALL_RIGHTS_* by the internal routines
		 * depending on the object type
		 */
		iacls.privileges = ACL_NO_RIGHTS;
	}
	else
	{
		iacls.all_privs = false;
		iacls.privileges = ACL_NO_RIGHTS;

		foreach(cell, action->privileges)
		{
			AccessPriv *privnode = (AccessPriv *) lfirst(cell);
			AclMode		priv;

			if (privnode->cols)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_GRANT_OPERATION),
					errmsg("default privileges cannot be set for columns")));

			if (privnode->priv_name == NULL)	/* parser mistake? */
				elog(ERROR, "AccessPriv node must specify privilege");
			priv = string_to_privilege(privnode->priv_name);

			if (priv & ~((AclMode) all_privileges))
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_GRANT_OPERATION),
						 errmsg(errormsg, privilege_to_string(priv))));

			iacls.privileges |= priv;
		}
	}

	if (rolenames == NIL)
	{
		/* Set permissions for myself */
		iacls.roleid = GetUserId();

		SetDefaultACLsInSchemas(&iacls, nspnames);
	}
	else
	{
		/* Look up the role OIDs and do permissions checks */
		ListCell   *rolecell;

		foreach(rolecell, rolenames)
		{
			char	   *rolename = strVal(lfirst(rolecell));

			iacls.roleid = get_role_oid(rolename, false);

			/*
			 * We insist that calling user be a member of each target role. If
			 * he has that, he could become that role anyway via SET ROLE, so
			 * FOR ROLE is just a syntactic convenience and doesn't give any
			 * special privileges.
			 */
			check_is_member_of_role(GetUserId(), iacls.roleid);

			SetDefaultACLsInSchemas(&iacls, nspnames);
		}
	}
}

/*
 * Process ALTER DEFAULT PRIVILEGES for a list of target schemas
 *
 * All fields of *iacls except nspid were filled already
 */
static void
SetDefaultACLsInSchemas(InternalDefaultACL *iacls, List *nspnames)
{
	if (nspnames == NIL)
	{
		/* Set database-wide permissions if no schema was specified */
		iacls->nspid = InvalidOid;

		SetDefaultACL(iacls);
	}
	else
	{
		/* Look up the schema OIDs and set permissions for each one */
		ListCell   *nspcell;

		foreach(nspcell, nspnames)
		{
			char	   *nspname = strVal(lfirst(nspcell));

			iacls->nspid = get_namespace_oid(nspname, false);

			/*
			 * We used to insist that the target role have CREATE privileges
			 * on the schema, since without that it wouldn't be able to create
			 * an object for which these default privileges would apply.
			 * However, this check proved to be more confusing than helpful,
			 * and it also caused certain database states to not be
			 * dumpable/restorable, since revoking CREATE doesn't cause
			 * default privileges for the schema to go away.  So now, we just
			 * allow the ALTER; if the user lacks CREATE he'll find out when
			 * he tries to create an object.
			 */

			SetDefaultACL(iacls);
		}
	}
}


/*
 * Create or update a pg_default_acl entry
 */
static void
SetDefaultACL(InternalDefaultACL *iacls)
{
	AclMode		this_privileges = iacls->privileges;
	char		objtype;
	Relation	rel;
	HeapTuple	tuple;
	bool		isNew;
	Acl		   *def_acl;
	Acl		   *old_acl;
	Acl		   *new_acl;
	HeapTuple	newtuple;
	Datum		values[Natts_pg_default_acl];
	bool		nulls[Natts_pg_default_acl];
	bool		replaces[Natts_pg_default_acl];
	int			noldmembers;
	int			nnewmembers;
	Oid		   *oldmembers;
	Oid		   *newmembers;

	rel = heap_open(DefaultAclRelationId, RowExclusiveLock);

	/*
	 * The default for a global entry is the hard-wired default ACL for the
	 * particular object type.	The default for non-global entries is an empty
	 * ACL.  This must be so because global entries replace the hard-wired
	 * defaults, while others are added on.
	 */
	if (!OidIsValid(iacls->nspid))
		def_acl = acldefault(iacls->objtype, iacls->roleid);
	else
		def_acl = make_empty_acl();

	/*
	 * Convert ACL object type to pg_default_acl object type and handle
	 * all_privs option
	 */
	switch (iacls->objtype)
	{
		case ACL_OBJECT_RELATION:
			objtype = DEFACLOBJ_RELATION;
			if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
				this_privileges = ACL_ALL_RIGHTS_RELATION;
			break;

		case ACL_OBJECT_SEQUENCE:
			objtype = DEFACLOBJ_SEQUENCE;
			if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
				this_privileges = ACL_ALL_RIGHTS_SEQUENCE;
			break;

		case ACL_OBJECT_FUNCTION:
			objtype = DEFACLOBJ_FUNCTION;
			if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
				this_privileges = ACL_ALL_RIGHTS_FUNCTION;
			break;

		default:
			elog(ERROR, "unrecognized objtype: %d",
				 (int) iacls->objtype);
			objtype = 0;		/* keep compiler quiet */
			break;
	}

	/* Search for existing row for this object type in catalog */
	tuple = SearchSysCache3(DEFACLROLENSPOBJ,
							ObjectIdGetDatum(iacls->roleid),
							ObjectIdGetDatum(iacls->nspid),
							CharGetDatum(objtype));

	if (HeapTupleIsValid(tuple))
	{
		Datum		aclDatum;
		bool		isNull;

		aclDatum = SysCacheGetAttr(DEFACLROLENSPOBJ, tuple,
								   Anum_pg_default_acl_defaclacl,
								   &isNull);
		if (!isNull)
			old_acl = DatumGetAclPCopy(aclDatum);
		else
			old_acl = NULL;		/* this case shouldn't happen, probably */
		isNew = false;
	}
	else
	{
		old_acl = NULL;
		isNew = true;
	}

	if (old_acl != NULL)
	{
		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.  Collect data before
		 * merge_acl_with_grant throws away old_acl.
		 */
		noldmembers = aclmembers(old_acl, &oldmembers);
	}
	else
	{
		/* If no or null entry, start with the default ACL value */
		old_acl = aclcopy(def_acl);
		/* There are no old member roles according to the catalogs */
		noldmembers = 0;
		oldmembers = NULL;
	}

	/*
	 * Generate new ACL.  Grantor of rights is always the same as the target
	 * role.
	 */
	new_acl = merge_acl_with_grant(old_acl,
								   iacls->is_grant,
								   iacls->grant_option,
								   iacls->behavior,
								   iacls->grantees,
								   this_privileges,
								   iacls->roleid,
								   iacls->roleid);

	/*
	 * If the result is the same as the default value, we do not need an
	 * explicit pg_default_acl entry, and should in fact remove the entry if
	 * it exists.  Must sort both arrays to compare properly.
	 */
	aclitemsort(new_acl);
	aclitemsort(def_acl);
	if (aclequal(new_acl, def_acl))
	{
		/* delete old entry, if indeed there is one */
		if (!isNew)
		{
			ObjectAddress myself;

			/*
			 * The dependency machinery will take care of removing all
			 * associated dependency entries.  We use DROP_RESTRICT since
			 * there shouldn't be anything depending on this entry.
			 */
			myself.classId = DefaultAclRelationId;
			myself.objectId = HeapTupleGetOid(tuple);
			myself.objectSubId = 0;

			performDeletion(&myself, DROP_RESTRICT);
		}
	}
	else
	{
		/* Prepare to insert or update pg_default_acl entry */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		if (isNew)
		{
			/* insert new entry */
			values[Anum_pg_default_acl_defaclrole - 1] = ObjectIdGetDatum(iacls->roleid);
			values[Anum_pg_default_acl_defaclnamespace - 1] = ObjectIdGetDatum(iacls->nspid);
			values[Anum_pg_default_acl_defaclobjtype - 1] = CharGetDatum(objtype);
			values[Anum_pg_default_acl_defaclacl - 1] = PointerGetDatum(new_acl);

			newtuple = heap_form_tuple(RelationGetDescr(rel), values, nulls);
			simple_heap_insert(rel, newtuple);
		}
		else
		{
			/* update existing entry */
			values[Anum_pg_default_acl_defaclacl - 1] = PointerGetDatum(new_acl);
			replaces[Anum_pg_default_acl_defaclacl - 1] = true;

			newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel),
										 values, nulls, replaces);
			simple_heap_update(rel, &newtuple->t_self, newtuple);
		}

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(rel, newtuple);

		/* these dependencies don't change in an update */
		if (isNew)
		{
			/* dependency on role */
			recordDependencyOnOwner(DefaultAclRelationId,
									HeapTupleGetOid(newtuple),
									iacls->roleid);

			/* dependency on namespace */
			if (OidIsValid(iacls->nspid))
			{
				ObjectAddress myself,
							referenced;

				myself.classId = DefaultAclRelationId;
				myself.objectId = HeapTupleGetOid(newtuple);
				myself.objectSubId = 0;

				referenced.classId = NamespaceRelationId;
				referenced.objectId = iacls->nspid;
				referenced.objectSubId = 0;

				recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
			}
		}

		/*
		 * Update the shared dependency ACL info
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		updateAclDependencies(DefaultAclRelationId,
							  HeapTupleGetOid(newtuple), 0,
							  iacls->roleid,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);
	}

	if (HeapTupleIsValid(tuple))
		ReleaseSysCache(tuple);

	heap_close(rel, RowExclusiveLock);
}


/*
 * RemoveRoleFromObjectACL
 *
 * Used by shdepDropOwned to remove mentions of a role in ACLs
 */
void
RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
{
	if (classid == DefaultAclRelationId)
	{
		InternalDefaultACL iacls;
		Form_pg_default_acl pg_default_acl_tuple;
		Relation	rel;
		ScanKeyData skey[1];
		SysScanDesc scan;
		HeapTuple	tuple;

		/* first fetch info needed by SetDefaultACL */
		rel = heap_open(DefaultAclRelationId, AccessShareLock);

		ScanKeyInit(&skey[0],
					ObjectIdAttributeNumber,
					BTEqualStrategyNumber, F_OIDEQ,
					ObjectIdGetDatum(objid));

		scan = systable_beginscan(rel, DefaultAclOidIndexId, true,
								  SnapshotNow, 1, skey);

		tuple = systable_getnext(scan);

		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "could not find tuple for default ACL %u", objid);

		pg_default_acl_tuple = (Form_pg_default_acl) GETSTRUCT(tuple);

		iacls.roleid = pg_default_acl_tuple->defaclrole;
		iacls.nspid = pg_default_acl_tuple->defaclnamespace;

		switch (pg_default_acl_tuple->defaclobjtype)
		{
			case DEFACLOBJ_RELATION:
				iacls.objtype = ACL_OBJECT_RELATION;
				break;
			case DEFACLOBJ_SEQUENCE:
				iacls.objtype = ACL_OBJECT_SEQUENCE;
				break;
			case DEFACLOBJ_FUNCTION:
				iacls.objtype = ACL_OBJECT_FUNCTION;
				break;
			default:
				/* Shouldn't get here */
				elog(ERROR, "unexpected default ACL type %d",
					 pg_default_acl_tuple->defaclobjtype);
				break;
		}

		systable_endscan(scan);
		heap_close(rel, AccessShareLock);

		iacls.is_grant = false;
		iacls.all_privs = true;
		iacls.privileges = ACL_NO_RIGHTS;
		iacls.grantees = list_make1_oid(roleid);
		iacls.grant_option = false;
		iacls.behavior = DROP_CASCADE;

		/* Do it */
		SetDefaultACL(&iacls);
	}
	else
	{
		InternalGrant istmt;

		switch (classid)
		{
			case RelationRelationId:
				/* it's OK to use RELATION for a sequence */
				istmt.objtype = ACL_OBJECT_RELATION;
				break;
			case DatabaseRelationId:
				istmt.objtype = ACL_OBJECT_DATABASE;
				break;
			case ProcedureRelationId:
				istmt.objtype = ACL_OBJECT_FUNCTION;
				break;
			case LanguageRelationId:
				istmt.objtype = ACL_OBJECT_LANGUAGE;
				break;
			case LargeObjectRelationId:
				istmt.objtype = ACL_OBJECT_LARGEOBJECT;
				break;
			case NamespaceRelationId:
				istmt.objtype = ACL_OBJECT_NAMESPACE;
				break;
			case TableSpaceRelationId:
				istmt.objtype = ACL_OBJECT_TABLESPACE;
				break;
			case ForeignServerRelationId:
				istmt.objtype = ACL_OBJECT_FOREIGN_SERVER;
				break;
			case ForeignDataWrapperRelationId:
				istmt.objtype = ACL_OBJECT_FDW;
				break;
			default:
				elog(ERROR, "unexpected object class %u", classid);
				break;
		}
		istmt.is_grant = false;
		istmt.objects = list_make1_oid(objid);
		istmt.all_privs = true;
		istmt.privileges = ACL_NO_RIGHTS;
		istmt.col_privs = NIL;
		istmt.grantees = list_make1_oid(roleid);
		istmt.grant_option = false;
		istmt.behavior = DROP_CASCADE;

		ExecGrantStmt_oids(&istmt);
	}
}


/*
 * Remove a pg_default_acl entry
 */
void
RemoveDefaultACLById(Oid defaclOid)
{
	Relation	rel;
	ScanKeyData skey[1];
	SysScanDesc scan;
	HeapTuple	tuple;

	rel = heap_open(DefaultAclRelationId, RowExclusiveLock);

	ScanKeyInit(&skey[0],
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(defaclOid));

	scan = systable_beginscan(rel, DefaultAclOidIndexId, true,
							  SnapshotNow, 1, skey);

	tuple = systable_getnext(scan);

	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "could not find tuple for default ACL %u", defaclOid);

	simple_heap_delete(rel, &tuple->t_self);

	systable_endscan(scan);
	heap_close(rel, RowExclusiveLock);
}


/*
 * expand_col_privileges
 *
 * OR the specified privilege(s) into per-column array entries for each
 * specified attribute.  The per-column array is indexed starting at
 * FirstLowInvalidHeapAttributeNumber, up to relation's last attribute.
 */
static void
expand_col_privileges(List *colnames, Oid table_oid,
					  AclMode this_privileges,
					  AclMode *col_privileges,
					  int num_col_privileges)
{
	ListCell   *cell;

	foreach(cell, colnames)
	{
		char	   *colname = strVal(lfirst(cell));
		AttrNumber	attnum;

		attnum = get_attnum(table_oid, colname);
		if (attnum == InvalidAttrNumber)
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_COLUMN),
					 errmsg("column \"%s\" of relation \"%s\" does not exist",
							colname, get_rel_name(table_oid))));
		attnum -= FirstLowInvalidHeapAttributeNumber;
		if (attnum <= 0 || attnum >= num_col_privileges)
			elog(ERROR, "column number out of range");	/* safety check */
		col_privileges[attnum] |= this_privileges;
	}
}

/*
 * expand_all_col_privileges
 *
 * OR the specified privilege(s) into per-column array entries for each valid
 * attribute of a relation.  The per-column array is indexed starting at
 * FirstLowInvalidHeapAttributeNumber, up to relation's last attribute.
 */
static void
expand_all_col_privileges(Oid table_oid, Form_pg_class classForm,
						  AclMode this_privileges,
						  AclMode *col_privileges,
						  int num_col_privileges)
{
	AttrNumber	curr_att;

	Assert(classForm->relnatts - FirstLowInvalidHeapAttributeNumber < num_col_privileges);
	for (curr_att = FirstLowInvalidHeapAttributeNumber + 1;
		 curr_att <= classForm->relnatts;
		 curr_att++)
	{
		HeapTuple	attTuple;
		bool		isdropped;

		if (curr_att == InvalidAttrNumber)
			continue;

		/* Skip OID column if it doesn't exist */
		if (curr_att == ObjectIdAttributeNumber && !classForm->relhasoids)
			continue;

		/* Views don't have any system columns at all */
		if (classForm->relkind == RELKIND_VIEW && curr_att < 0)
			continue;

		attTuple = SearchSysCache2(ATTNUM,
								   ObjectIdGetDatum(table_oid),
								   Int16GetDatum(curr_att));
		if (!HeapTupleIsValid(attTuple))
			elog(ERROR, "cache lookup failed for attribute %d of relation %u",
				 curr_att, table_oid);

		isdropped = ((Form_pg_attribute) GETSTRUCT(attTuple))->attisdropped;

		ReleaseSysCache(attTuple);

		/* ignore dropped columns */
		if (isdropped)
			continue;

		col_privileges[curr_att - FirstLowInvalidHeapAttributeNumber] |= this_privileges;
	}
}

/*
 *	This processes attributes, but expects to be called from
 *	ExecGrant_Relation, not directly from ExecGrantStmt.
 */
static void
ExecGrant_Attribute(InternalGrant *istmt, Oid relOid, const char *relname,
					AttrNumber attnum, Oid ownerId, AclMode col_privileges,
					Relation attRelation, const Acl *old_rel_acl)
{
	HeapTuple	attr_tuple;
	Form_pg_attribute pg_attribute_tuple;
	Acl		   *old_acl;
	Acl		   *new_acl;
	Acl		   *merged_acl;
	Datum		aclDatum;
	bool		isNull;
	Oid			grantorId;
	AclMode		avail_goptions;
	bool		need_update;
	HeapTuple	newtuple;
	Datum		values[Natts_pg_attribute];
	bool		nulls[Natts_pg_attribute];
	bool		replaces[Natts_pg_attribute];
	int			noldmembers;
	int			nnewmembers;
	Oid		   *oldmembers;
	Oid		   *newmembers;

	attr_tuple = SearchSysCache2(ATTNUM,
								 ObjectIdGetDatum(relOid),
								 Int16GetDatum(attnum));
	if (!HeapTupleIsValid(attr_tuple))
		elog(ERROR, "cache lookup failed for attribute %d of relation %u",
			 attnum, relOid);
	pg_attribute_tuple = (Form_pg_attribute) GETSTRUCT(attr_tuple);

	/*
	 * Get working copy of existing ACL. If there's no ACL, substitute the
	 * proper default.
	 */
	aclDatum = SysCacheGetAttr(ATTNUM, attr_tuple, Anum_pg_attribute_attacl,
							   &isNull);
	if (isNull)
	{
		old_acl = acldefault(ACL_OBJECT_COLUMN, ownerId);
		/* There are no old member roles according to the catalogs */
		noldmembers = 0;
		oldmembers = NULL;
	}
	else
	{
		old_acl = DatumGetAclPCopy(aclDatum);
		/* Get the roles mentioned in the existing ACL */
		noldmembers = aclmembers(old_acl, &oldmembers);
	}

	/*
	 * In select_best_grantor we should consider existing table-level ACL bits
	 * as well as the per-column ACL.  Build a new ACL that is their
	 * concatenation.  (This is a bit cheap and dirty compared to merging them
	 * properly with no duplications, but it's all we need here.)
	 */
	merged_acl = aclconcat(old_rel_acl, old_acl);

	/* Determine ID to do the grant as, and available grant options */
	select_best_grantor(GetUserId(), col_privileges,
						merged_acl, ownerId,
						&grantorId, &avail_goptions);

	pfree(merged_acl);

	/*
	 * Restrict the privileges to what we can actually grant, and emit the
	 * standards-mandated warning and error messages.  Note: we don't track
	 * whether the user actually used the ALL PRIVILEGES(columns) syntax for
	 * each column; we just approximate it by whether all the possible
	 * privileges are specified now.  Since the all_privs flag only determines
	 * whether a warning is issued, this seems close enough.
	 */
	col_privileges =
		restrict_and_check_grant(istmt->is_grant, avail_goptions,
								 (col_privileges == ACL_ALL_RIGHTS_COLUMN),
								 col_privileges,
								 relOid, grantorId, ACL_KIND_COLUMN,
								 relname, attnum,
								 NameStr(pg_attribute_tuple->attname));

	/*
	 * Generate new ACL.
	 */
	new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
								   istmt->grant_option,
								   istmt->behavior, istmt->grantees,
								   col_privileges, grantorId,
								   ownerId);

	/*
	 * We need the members of both old and new ACLs so we can correct the
	 * shared dependency information.
	 */
	nnewmembers = aclmembers(new_acl, &newmembers);

	/* finished building new ACL value, now insert it */
	MemSet(values, 0, sizeof(values));
	MemSet(nulls, false, sizeof(nulls));
	MemSet(replaces, false, sizeof(replaces));

	/*
	 * If the updated ACL is empty, we can set attacl to null, and maybe even
	 * avoid an update of the pg_attribute row.  This is worth testing because
	 * we'll come through here multiple times for any relation-level REVOKE,
	 * even if there were never any column GRANTs.	Note we are assuming that
	 * the "default" ACL state for columns is empty.
	 */
	if (ACL_NUM(new_acl) > 0)
	{
		values[Anum_pg_attribute_attacl - 1] = PointerGetDatum(new_acl);
		need_update = true;
	}
	else
	{
		nulls[Anum_pg_attribute_attacl - 1] = true;
		need_update = !isNull;
	}
	replaces[Anum_pg_attribute_attacl - 1] = true;

	if (need_update)
	{
		newtuple = heap_modify_tuple(attr_tuple, RelationGetDescr(attRelation),
									 values, nulls, replaces);

		simple_heap_update(attRelation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(attRelation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(RelationRelationId, relOid, attnum,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);
	}

	pfree(new_acl);

	ReleaseSysCache(attr_tuple);
}

/*
 *	This processes both sequences and non-sequences.
 */
static void
ExecGrant_Relation(InternalGrant *istmt)
{
	Relation	relation;
	Relation	attRelation;
	ListCell   *cell;

	relation = heap_open(RelationRelationId, RowExclusiveLock);
	attRelation = heap_open(AttributeRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			relOid = lfirst_oid(cell);
		Datum		aclDatum;
		Form_pg_class pg_class_tuple;
		bool		isNull;
		AclMode		this_privileges;
		AclMode    *col_privileges;
		int			num_col_privileges;
		bool		have_col_privileges;
		Acl		   *old_acl;
		Acl		   *old_rel_acl;
		int			noldmembers;
		Oid		   *oldmembers;
		Oid			ownerId;
		HeapTuple	tuple;
		ListCell   *cell_colprivs;

		tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for relation %u", relOid);
		pg_class_tuple = (Form_pg_class) GETSTRUCT(tuple);

		/* Not sensible to grant on an index */
		if (pg_class_tuple->relkind == RELKIND_INDEX)
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("\"%s\" is an index",
							NameStr(pg_class_tuple->relname))));

		/* Composite types aren't tables either */
		if (pg_class_tuple->relkind == RELKIND_COMPOSITE_TYPE)
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("\"%s\" is a composite type",
							NameStr(pg_class_tuple->relname))));

		/* Used GRANT SEQUENCE on a non-sequence? */
		if (istmt->objtype == ACL_OBJECT_SEQUENCE &&
			pg_class_tuple->relkind != RELKIND_SEQUENCE)
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("\"%s\" is not a sequence",
							NameStr(pg_class_tuple->relname))));

		/* Adjust the default permissions based on object type */
		if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		{
			if (pg_class_tuple->relkind == RELKIND_SEQUENCE)
				this_privileges = ACL_ALL_RIGHTS_SEQUENCE;
			else
				this_privileges = ACL_ALL_RIGHTS_RELATION;
		}
		else
			this_privileges = istmt->privileges;

		/*
		 * The GRANT TABLE syntax can be used for sequences and non-sequences,
		 * so we have to look at the relkind to determine the supported
		 * permissions.  The OR of table and sequence permissions were already
		 * checked.
		 */
		if (istmt->objtype == ACL_OBJECT_RELATION)
		{
			if (pg_class_tuple->relkind == RELKIND_SEQUENCE)
			{
				/*
				 * For backward compatibility, just throw a warning for
				 * invalid sequence permissions when using the non-sequence
				 * GRANT syntax.
				 */
				if (this_privileges & ~((AclMode) ACL_ALL_RIGHTS_SEQUENCE))
				{
					/*
					 * Mention the object name because the user needs to know
					 * which operations succeeded.	This is required because
					 * WARNING allows the command to continue.
					 */
					ereport(WARNING,
							(errcode(ERRCODE_INVALID_GRANT_OPERATION),
							 errmsg("sequence \"%s\" only supports USAGE, SELECT, and UPDATE privileges",
									NameStr(pg_class_tuple->relname))));
					this_privileges &= (AclMode) ACL_ALL_RIGHTS_SEQUENCE;
				}
			}
			else
			{
				if (this_privileges & ~((AclMode) ACL_ALL_RIGHTS_RELATION))
				{
					/*
					 * USAGE is the only permission supported by sequences but
					 * not by non-sequences.  Don't mention the object name
					 * because we didn't in the combined TABLE | SEQUENCE
					 * check.
					 */
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_GRANT_OPERATION),
						  errmsg("invalid privilege type USAGE for table")));
				}
			}
		}

		/*
		 * Set up array in which we'll accumulate any column privilege bits
		 * that need modification.	The array is indexed such that entry [0]
		 * corresponds to FirstLowInvalidHeapAttributeNumber.
		 */
		num_col_privileges = pg_class_tuple->relnatts - FirstLowInvalidHeapAttributeNumber + 1;
		col_privileges = (AclMode *) palloc0(num_col_privileges * sizeof(AclMode));
		have_col_privileges = false;

		/*
		 * If we are revoking relation privileges that are also column
		 * privileges, we must implicitly revoke them from each column too,
		 * per SQL spec.  (We don't need to implicitly add column privileges
		 * during GRANT because the permissions-checking code always checks
		 * both relation and per-column privileges.)
		 */
		if (!istmt->is_grant &&
			(this_privileges & ACL_ALL_RIGHTS_COLUMN) != 0)
		{
			expand_all_col_privileges(relOid, pg_class_tuple,
									  this_privileges & ACL_ALL_RIGHTS_COLUMN,
									  col_privileges,
									  num_col_privileges);
			have_col_privileges = true;
		}

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_class_tuple->relowner;
		aclDatum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relacl,
								   &isNull);
		if (isNull)
		{
			switch (pg_class_tuple->relkind)
			{
				case RELKIND_SEQUENCE:
					old_acl = acldefault(ACL_OBJECT_SEQUENCE, ownerId);
					break;
				default:
					old_acl = acldefault(ACL_OBJECT_RELATION, ownerId);
					break;
			}
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Need an extra copy of original rel ACL for column handling */
		old_rel_acl = aclcopy(old_acl);

		/*
		 * Handle relation-level privileges, if any were specified
		 */
		if (this_privileges != ACL_NO_RIGHTS)
		{
			AclMode		avail_goptions;
			Acl		   *new_acl;
			Oid			grantorId;
			HeapTuple	newtuple;
			Datum		values[Natts_pg_class];
			bool		nulls[Natts_pg_class];
			bool		replaces[Natts_pg_class];
			int			nnewmembers;
			Oid		   *newmembers;
			AclObjectKind aclkind;

			/* Determine ID to do the grant as, and available grant options */
			select_best_grantor(GetUserId(), this_privileges,
								old_acl, ownerId,
								&grantorId, &avail_goptions);

			switch (pg_class_tuple->relkind)
			{
				case RELKIND_SEQUENCE:
					aclkind = ACL_KIND_SEQUENCE;
					break;
				default:
					aclkind = ACL_KIND_CLASS;
					break;
			}

			/*
			 * Restrict the privileges to what we can actually grant, and emit
			 * the standards-mandated warning and error messages.
			 */
			this_privileges =
				restrict_and_check_grant(istmt->is_grant, avail_goptions,
										 istmt->all_privs, this_privileges,
										 relOid, grantorId, aclkind,
										 NameStr(pg_class_tuple->relname),
										 0, NULL);

			/*
			 * Generate new ACL.
			 */
			new_acl = merge_acl_with_grant(old_acl,
										   istmt->is_grant,
										   istmt->grant_option,
										   istmt->behavior,
										   istmt->grantees,
										   this_privileges,
										   grantorId,
										   ownerId);

			/*
			 * We need the members of both old and new ACLs so we can correct
			 * the shared dependency information.
			 */
			nnewmembers = aclmembers(new_acl, &newmembers);

			/* finished building new ACL value, now insert it */
			MemSet(values, 0, sizeof(values));
			MemSet(nulls, false, sizeof(nulls));
			MemSet(replaces, false, sizeof(replaces));

			replaces[Anum_pg_class_relacl - 1] = true;
			values[Anum_pg_class_relacl - 1] = PointerGetDatum(new_acl);

			newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation),
										 values, nulls, replaces);

			simple_heap_update(relation, &newtuple->t_self, newtuple);

			/* keep the catalog indexes up to date */
			CatalogUpdateIndexes(relation, newtuple);

			/* Update the shared dependency ACL info */
			updateAclDependencies(RelationRelationId, relOid, 0,
								  ownerId,
								  noldmembers, oldmembers,
								  nnewmembers, newmembers);

			pfree(new_acl);
		}

		/*
		 * Handle column-level privileges, if any were specified or implied.
		 * We first expand the user-specified column privileges into the
		 * array, and then iterate over all nonempty array entries.
		 */
		foreach(cell_colprivs, istmt->col_privs)
		{
			AccessPriv *col_privs = (AccessPriv *) lfirst(cell_colprivs);

			if (col_privs->priv_name == NULL)
				this_privileges = ACL_ALL_RIGHTS_COLUMN;
			else
				this_privileges = string_to_privilege(col_privs->priv_name);

			if (this_privileges & ~((AclMode) ACL_ALL_RIGHTS_COLUMN))
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_GRANT_OPERATION),
						 errmsg("invalid privilege type %s for column",
								privilege_to_string(this_privileges))));

			if (pg_class_tuple->relkind == RELKIND_SEQUENCE &&
				this_privileges & ~((AclMode) ACL_SELECT))
			{
				/*
				 * The only column privilege allowed on sequences is SELECT.
				 * This is a warning not error because we do it that way for
				 * relation-level privileges.
				 */
				ereport(WARNING,
						(errcode(ERRCODE_INVALID_GRANT_OPERATION),
						 errmsg("sequence \"%s\" only supports SELECT column privileges",
								NameStr(pg_class_tuple->relname))));

				this_privileges &= (AclMode) ACL_SELECT;
			}

			expand_col_privileges(col_privs->cols, relOid,
								  this_privileges,
								  col_privileges,
								  num_col_privileges);
			have_col_privileges = true;
		}

		if (have_col_privileges)
		{
			AttrNumber	i;

			for (i = 0; i < num_col_privileges; i++)
			{
				if (col_privileges[i] == ACL_NO_RIGHTS)
					continue;
				ExecGrant_Attribute(istmt,
									relOid,
									NameStr(pg_class_tuple->relname),
									i + FirstLowInvalidHeapAttributeNumber,
									ownerId,
									col_privileges[i],
									attRelation,
									old_rel_acl);
			}
		}

		pfree(old_rel_acl);
		pfree(col_privileges);

		ReleaseSysCache(tuple);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(attRelation, RowExclusiveLock);
	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Database(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_DATABASE;

	relation = heap_open(DatabaseRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			datId = lfirst_oid(cell);
		Form_pg_database pg_database_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_database];
		bool		nulls[Natts_pg_database];
		bool		replaces[Natts_pg_database];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;
		HeapTuple	tuple;

		tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(datId));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for database %u", datId);

		pg_database_tuple = (Form_pg_database) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_database_tuple->datdba;
		aclDatum = heap_getattr(tuple, Anum_pg_database_datacl,
								RelationGetDescr(relation), &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_DATABASE, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 datId, grantorId, ACL_KIND_DATABASE,
									 NameStr(pg_database_tuple->datname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_database_datacl - 1] = true;
		values[Anum_pg_database_datacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(DatabaseRelationId, HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Fdw(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_FDW;

	relation = heap_open(ForeignDataWrapperRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			fdwid = lfirst_oid(cell);
		Form_pg_foreign_data_wrapper pg_fdw_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	tuple;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_foreign_data_wrapper];
		bool		nulls[Natts_pg_foreign_data_wrapper];
		bool		replaces[Natts_pg_foreign_data_wrapper];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;

		tuple = SearchSysCache1(FOREIGNDATAWRAPPEROID,
								ObjectIdGetDatum(fdwid));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for foreign-data wrapper %u", fdwid);

		pg_fdw_tuple = (Form_pg_foreign_data_wrapper) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_fdw_tuple->fdwowner;
		aclDatum = SysCacheGetAttr(FOREIGNDATAWRAPPEROID, tuple,
								   Anum_pg_foreign_data_wrapper_fdwacl,
								   &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_FDW, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 fdwid, grantorId, ACL_KIND_FDW,
									 NameStr(pg_fdw_tuple->fdwname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_foreign_data_wrapper_fdwacl - 1] = true;
		values[Anum_pg_foreign_data_wrapper_fdwacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(ForeignDataWrapperRelationId,
							  HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_ForeignServer(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_FOREIGN_SERVER;

	relation = heap_open(ForeignServerRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			srvid = lfirst_oid(cell);
		Form_pg_foreign_server pg_server_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	tuple;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_foreign_server];
		bool		nulls[Natts_pg_foreign_server];
		bool		replaces[Natts_pg_foreign_server];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;

		tuple = SearchSysCache1(FOREIGNSERVEROID, ObjectIdGetDatum(srvid));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for foreign server %u", srvid);

		pg_server_tuple = (Form_pg_foreign_server) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_server_tuple->srvowner;
		aclDatum = SysCacheGetAttr(FOREIGNSERVEROID, tuple,
								   Anum_pg_foreign_server_srvacl,
								   &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_FOREIGN_SERVER, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
								   srvid, grantorId, ACL_KIND_FOREIGN_SERVER,
									 NameStr(pg_server_tuple->srvname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_foreign_server_srvacl - 1] = true;
		values[Anum_pg_foreign_server_srvacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(ForeignServerRelationId,
							  HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Function(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_FUNCTION;

	relation = heap_open(ProcedureRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			funcId = lfirst_oid(cell);
		Form_pg_proc pg_proc_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	tuple;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_proc];
		bool		nulls[Natts_pg_proc];
		bool		replaces[Natts_pg_proc];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;

		tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcId));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for function %u", funcId);

		pg_proc_tuple = (Form_pg_proc) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_proc_tuple->proowner;
		aclDatum = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_proacl,
								   &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_FUNCTION, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 funcId, grantorId, ACL_KIND_PROC,
									 NameStr(pg_proc_tuple->proname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_proc_proacl - 1] = true;
		values[Anum_pg_proc_proacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(ProcedureRelationId, funcId, 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Language(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_LANGUAGE;

	relation = heap_open(LanguageRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			langId = lfirst_oid(cell);
		Form_pg_language pg_language_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	tuple;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_language];
		bool		nulls[Natts_pg_language];
		bool		replaces[Natts_pg_language];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;

		tuple = SearchSysCache1(LANGOID, ObjectIdGetDatum(langId));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for language %u", langId);

		pg_language_tuple = (Form_pg_language) GETSTRUCT(tuple);

		if (!pg_language_tuple->lanpltrusted)
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("language \"%s\" is not trusted",
							NameStr(pg_language_tuple->lanname)),
				   errhint("Only superusers can use untrusted languages.")));

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_language_tuple->lanowner;
		aclDatum = SysCacheGetAttr(LANGNAME, tuple, Anum_pg_language_lanacl,
								   &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_LANGUAGE, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 langId, grantorId, ACL_KIND_LANGUAGE,
									 NameStr(pg_language_tuple->lanname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_language_lanacl - 1] = true;
		values[Anum_pg_language_lanacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(LanguageRelationId, HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Largeobject(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_LARGEOBJECT;

	relation = heap_open(LargeObjectMetadataRelationId,
						 RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			loid = lfirst_oid(cell);
		Form_pg_largeobject_metadata form_lo_meta;
		char		loname[NAMEDATALEN];
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_largeobject_metadata];
		bool		nulls[Natts_pg_largeobject_metadata];
		bool		replaces[Natts_pg_largeobject_metadata];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;
		ScanKeyData entry[1];
		SysScanDesc scan;
		HeapTuple	tuple;

		/* There's no syscache for pg_largeobject_metadata */
		ScanKeyInit(&entry[0],
					ObjectIdAttributeNumber,
					BTEqualStrategyNumber, F_OIDEQ,
					ObjectIdGetDatum(loid));

		scan = systable_beginscan(relation,
								  LargeObjectMetadataOidIndexId, true,
								  SnapshotNow, 1, entry);

		tuple = systable_getnext(scan);
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for large object %u", loid);

		form_lo_meta = (Form_pg_largeobject_metadata) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = form_lo_meta->lomowner;
		aclDatum = heap_getattr(tuple,
								Anum_pg_largeobject_metadata_lomacl,
								RelationGetDescr(relation), &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_LARGEOBJECT, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		snprintf(loname, sizeof(loname), "large object %u", loid);
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 loid, grantorId, ACL_KIND_LARGEOBJECT,
									 loname, 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_largeobject_metadata_lomacl - 1] = true;
		values[Anum_pg_largeobject_metadata_lomacl - 1]
			= PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation),
									 values, nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(LargeObjectRelationId,
							  HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		systable_endscan(scan);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Namespace(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_NAMESPACE;

	relation = heap_open(NamespaceRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			nspid = lfirst_oid(cell);
		Form_pg_namespace pg_namespace_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	tuple;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_namespace];
		bool		nulls[Natts_pg_namespace];
		bool		replaces[Natts_pg_namespace];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;

		tuple = SearchSysCache1(NAMESPACEOID, ObjectIdGetDatum(nspid));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for namespace %u", nspid);

		pg_namespace_tuple = (Form_pg_namespace) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_namespace_tuple->nspowner;
		aclDatum = SysCacheGetAttr(NAMESPACENAME, tuple,
								   Anum_pg_namespace_nspacl,
								   &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_NAMESPACE, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 nspid, grantorId, ACL_KIND_NAMESPACE,
									 NameStr(pg_namespace_tuple->nspname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_namespace_nspacl - 1] = true;
		values[Anum_pg_namespace_nspacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(NamespaceRelationId, HeapTupleGetOid(tuple), 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);

		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}

static void
ExecGrant_Tablespace(InternalGrant *istmt)
{
	Relation	relation;
	ListCell   *cell;

	if (istmt->all_privs && istmt->privileges == ACL_NO_RIGHTS)
		istmt->privileges = ACL_ALL_RIGHTS_TABLESPACE;

	relation = heap_open(TableSpaceRelationId, RowExclusiveLock);

	foreach(cell, istmt->objects)
	{
		Oid			tblId = lfirst_oid(cell);
		Form_pg_tablespace pg_tablespace_tuple;
		Datum		aclDatum;
		bool		isNull;
		AclMode		avail_goptions;
		AclMode		this_privileges;
		Acl		   *old_acl;
		Acl		   *new_acl;
		Oid			grantorId;
		Oid			ownerId;
		HeapTuple	newtuple;
		Datum		values[Natts_pg_tablespace];
		bool		nulls[Natts_pg_tablespace];
		bool		replaces[Natts_pg_tablespace];
		int			noldmembers;
		int			nnewmembers;
		Oid		   *oldmembers;
		Oid		   *newmembers;
		HeapTuple	tuple;

		/* Search syscache for pg_tablespace */
		tuple = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(tblId));
		if (!HeapTupleIsValid(tuple))
			elog(ERROR, "cache lookup failed for tablespace %u", tblId);

		pg_tablespace_tuple = (Form_pg_tablespace) GETSTRUCT(tuple);

		/*
		 * Get owner ID and working copy of existing ACL. If there's no ACL,
		 * substitute the proper default.
		 */
		ownerId = pg_tablespace_tuple->spcowner;
		aclDatum = heap_getattr(tuple, Anum_pg_tablespace_spcacl,
								RelationGetDescr(relation), &isNull);
		if (isNull)
		{
			old_acl = acldefault(ACL_OBJECT_TABLESPACE, ownerId);
			/* There are no old member roles according to the catalogs */
			noldmembers = 0;
			oldmembers = NULL;
		}
		else
		{
			old_acl = DatumGetAclPCopy(aclDatum);
			/* Get the roles mentioned in the existing ACL */
			noldmembers = aclmembers(old_acl, &oldmembers);
		}

		/* Determine ID to do the grant as, and available grant options */
		select_best_grantor(GetUserId(), istmt->privileges,
							old_acl, ownerId,
							&grantorId, &avail_goptions);

		/*
		 * Restrict the privileges to what we can actually grant, and emit the
		 * standards-mandated warning and error messages.
		 */
		this_privileges =
			restrict_and_check_grant(istmt->is_grant, avail_goptions,
									 istmt->all_privs, istmt->privileges,
									 tblId, grantorId, ACL_KIND_TABLESPACE,
									 NameStr(pg_tablespace_tuple->spcname),
									 0, NULL);

		/*
		 * Generate new ACL.
		 */
		new_acl = merge_acl_with_grant(old_acl, istmt->is_grant,
									   istmt->grant_option, istmt->behavior,
									   istmt->grantees, this_privileges,
									   grantorId, ownerId);

		/*
		 * We need the members of both old and new ACLs so we can correct the
		 * shared dependency information.
		 */
		nnewmembers = aclmembers(new_acl, &newmembers);

		/* finished building new ACL value, now insert it */
		MemSet(values, 0, sizeof(values));
		MemSet(nulls, false, sizeof(nulls));
		MemSet(replaces, false, sizeof(replaces));

		replaces[Anum_pg_tablespace_spcacl - 1] = true;
		values[Anum_pg_tablespace_spcacl - 1] = PointerGetDatum(new_acl);

		newtuple = heap_modify_tuple(tuple, RelationGetDescr(relation), values,
									 nulls, replaces);

		simple_heap_update(relation, &newtuple->t_self, newtuple);

		/* keep the catalog indexes up to date */
		CatalogUpdateIndexes(relation, newtuple);

		/* Update the shared dependency ACL info */
		updateAclDependencies(TableSpaceRelationId, tblId, 0,
							  ownerId,
							  noldmembers, oldmembers,
							  nnewmembers, newmembers);

		ReleaseSysCache(tuple);
		pfree(new_acl);

		/* prevent error when processing duplicate objects */
		CommandCounterIncrement();
	}

	heap_close(relation, RowExclusiveLock);
}


static AclMode
string_to_privilege(const char *privname)
{
	if (strcmp(privname, "insert") == 0)
		return ACL_INSERT;
	if (strcmp(privname, "select") == 0)
		return ACL_SELECT;
	if (strcmp(privname, "update") == 0)
		return ACL_UPDATE;
	if (strcmp(privname, "delete") == 0)
		return ACL_DELETE;
	if (strcmp(privname, "truncate") == 0)
		return ACL_TRUNCATE;
	if (strcmp(privname, "references") == 0)
		return ACL_REFERENCES;
	if (strcmp(privname, "trigger") == 0)
		return ACL_TRIGGER;
	if (strcmp(privname, "execute") == 0)
		return ACL_EXECUTE;
	if (strcmp(privname, "usage") == 0)
		return ACL_USAGE;
	if (strcmp(privname, "create") == 0)
		return ACL_CREATE;
	if (strcmp(privname, "temporary") == 0)
		return ACL_CREATE_TEMP;
	if (strcmp(privname, "temp") == 0)
		return ACL_CREATE_TEMP;
	if (strcmp(privname, "connect") == 0)
		return ACL_CONNECT;
	if (strcmp(privname, "rule") == 0)
		return 0;				/* ignore old RULE privileges */
	ereport(ERROR,
			(errcode(ERRCODE_SYNTAX_ERROR),
			 errmsg("unrecognized privilege type \"%s\"", privname)));
	return 0;					/* appease compiler */
}

static const char *
privilege_to_string(AclMode privilege)
{
	switch (privilege)
	{
		case ACL_INSERT:
			return "INSERT";
		case ACL_SELECT:
			return "SELECT";
		case ACL_UPDATE:
			return "UPDATE";
		case ACL_DELETE:
			return "DELETE";
		case ACL_TRUNCATE:
			return "TRUNCATE";
		case ACL_REFERENCES:
			return "REFERENCES";
		case ACL_TRIGGER:
			return "TRIGGER";
		case ACL_EXECUTE:
			return "EXECUTE";
		case ACL_USAGE:
			return "USAGE";
		case ACL_CREATE:
			return "CREATE";
		case ACL_CREATE_TEMP:
			return "TEMP";
		case ACL_CONNECT:
			return "CONNECT";
		default:
			elog(ERROR, "unrecognized privilege: %d", (int) privilege);
	}
	return NULL;				/* appease compiler */
}

/*
 * Standardized reporting of aclcheck permissions failures.
 *
 * Note: we do not double-quote the %s's below, because many callers
 * supply strings that might be already quoted.
 */

static const char *const no_priv_msg[MAX_ACL_KIND] =
{
	/* ACL_KIND_COLUMN */
	gettext_noop("permission denied for column %s"),
	/* ACL_KIND_CLASS */
	gettext_noop("permission denied for relation %s"),
	/* ACL_KIND_SEQUENCE */
	gettext_noop("permission denied for sequence %s"),
	/* ACL_KIND_DATABASE */
	gettext_noop("permission denied for database %s"),
	/* ACL_KIND_PROC */
	gettext_noop("permission denied for function %s"),
	/* ACL_KIND_OPER */
	gettext_noop("permission denied for operator %s"),
	/* ACL_KIND_TYPE */
	gettext_noop("permission denied for type %s"),
	/* ACL_KIND_LANGUAGE */
	gettext_noop("permission denied for language %s"),
	/* ACL_KIND_LARGEOBJECT */
	gettext_noop("permission denied for large object %s"),
	/* ACL_KIND_NAMESPACE */
	gettext_noop("permission denied for schema %s"),
	/* ACL_KIND_OPCLASS */
	gettext_noop("permission denied for operator class %s"),
	/* ACL_KIND_OPFAMILY */
	gettext_noop("permission denied for operator family %s"),
	/* ACL_KIND_COLLATION */
	gettext_noop("permission denied for collation %s"),
	/* ACL_KIND_CONVERSION */
	gettext_noop("permission denied for conversion %s"),
	/* ACL_KIND_TABLESPACE */
	gettext_noop("permission denied for tablespace %s"),
	/* ACL_KIND_TSDICTIONARY */
	gettext_noop("permission denied for text search dictionary %s"),
	/* ACL_KIND_TSCONFIGURATION */
	gettext_noop("permission denied for text search configuration %s"),
	/* ACL_KIND_FDW */
	gettext_noop("permission denied for foreign-data wrapper %s"),
	/* ACL_KIND_FOREIGN_SERVER */
	gettext_noop("permission denied for foreign server %s"),
	/* ACL_KIND_EXTENSION */
	gettext_noop("permission denied for extension %s"),
};

static const char *const not_owner_msg[MAX_ACL_KIND] =
{
	/* ACL_KIND_COLUMN */
	gettext_noop("must be owner of relation %s"),
	/* ACL_KIND_CLASS */
	gettext_noop("must be owner of relation %s"),
	/* ACL_KIND_SEQUENCE */
	gettext_noop("must be owner of sequence %s"),
	/* ACL_KIND_DATABASE */
	gettext_noop("must be owner of database %s"),
	/* ACL_KIND_PROC */
	gettext_noop("must be owner of function %s"),
	/* ACL_KIND_OPER */
	gettext_noop("must be owner of operator %s"),
	/* ACL_KIND_TYPE */
	gettext_noop("must be owner of type %s"),
	/* ACL_KIND_LANGUAGE */
	gettext_noop("must be owner of language %s"),
	/* ACL_KIND_LARGEOBJECT */
	gettext_noop("must be owner of large object %s"),
	/* ACL_KIND_NAMESPACE */
	gettext_noop("must be owner of schema %s"),
	/* ACL_KIND_OPCLASS */
	gettext_noop("must be owner of operator class %s"),
	/* ACL_KIND_OPFAMILY */
	gettext_noop("must be owner of operator family %s"),
	/* ACL_KIND_COLLATION */
	gettext_noop("must be owner of collation %s"),
	/* ACL_KIND_CONVERSION */
	gettext_noop("must be owner of conversion %s"),
	/* ACL_KIND_TABLESPACE */
	gettext_noop("must be owner of tablespace %s"),
	/* ACL_KIND_TSDICTIONARY */
	gettext_noop("must be owner of text search dictionary %s"),
	/* ACL_KIND_TSCONFIGURATION */
	gettext_noop("must be owner of text search configuration %s"),
	/* ACL_KIND_FDW */
	gettext_noop("must be owner of foreign-data wrapper %s"),
	/* ACL_KIND_FOREIGN_SERVER */
	gettext_noop("must be owner of foreign server %s"),
	/* ACL_KIND_EXTENSION */
	gettext_noop("must be owner of extension %s"),
};


void
aclcheck_error(AclResult aclerr, AclObjectKind objectkind,
			   const char *objectname)
{
	switch (aclerr)
	{
		case ACLCHECK_OK:
			/* no error, so return to caller */
			break;
		case ACLCHECK_NO_PRIV:
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
					 errmsg(no_priv_msg[objectkind], objectname)));
			break;
		case ACLCHECK_NOT_OWNER:
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
					 errmsg(not_owner_msg[objectkind], objectname)));
			break;
		default:
			elog(ERROR, "unrecognized AclResult: %d", (int) aclerr);
			break;
	}
}


void
aclcheck_error_col(AclResult aclerr, AclObjectKind objectkind,
				   const char *objectname, const char *colname)
{
	switch (aclerr)
	{
		case ACLCHECK_OK:
			/* no error, so return to caller */
			break;
		case ACLCHECK_NO_PRIV:
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
			 errmsg("permission denied for column \"%s\" of relation \"%s\"",
					colname, objectname)));
			break;
		case ACLCHECK_NOT_OWNER:
			/* relation msg is OK since columns don't have separate owners */
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
					 errmsg(not_owner_msg[objectkind], objectname)));
			break;
		default:
			elog(ERROR, "unrecognized AclResult: %d", (int) aclerr);
			break;
	}
}


/* Check if given user has rolcatupdate privilege according to pg_authid */
static bool
has_rolcatupdate(Oid roleid)
{
	bool		rolcatupdate;
	HeapTuple	tuple;

	tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("role with OID %u does not exist", roleid)));

	rolcatupdate = ((Form_pg_authid) GETSTRUCT(tuple))->rolcatupdate;

	ReleaseSysCache(tuple);

	return rolcatupdate;
}

/*
 * Relay for the various pg_*_mask routines depending on object kind
 */
static AclMode
pg_aclmask(AclObjectKind objkind, Oid table_oid, AttrNumber attnum, Oid roleid,
		   AclMode mask, AclMaskHow how)
{
	switch (objkind)
	{
		case ACL_KIND_COLUMN:
			return
				pg_class_aclmask(table_oid, roleid, mask, how) |
				pg_attribute_aclmask(table_oid, attnum, roleid, mask, how);
		case ACL_KIND_CLASS:
		case ACL_KIND_SEQUENCE:
			return pg_class_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_DATABASE:
			return pg_database_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_PROC:
			return pg_proc_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_LANGUAGE:
			return pg_language_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_LARGEOBJECT:
			return pg_largeobject_aclmask_snapshot(table_oid, roleid,
												   mask, how, SnapshotNow);
		case ACL_KIND_NAMESPACE:
			return pg_namespace_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_TABLESPACE:
			return pg_tablespace_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_FDW:
			return pg_foreign_data_wrapper_aclmask(table_oid, roleid, mask, how);
		case ACL_KIND_FOREIGN_SERVER:
			return pg_foreign_server_aclmask(table_oid, roleid, mask, how);
		default:
			elog(ERROR, "unrecognized objkind: %d",
				 (int) objkind);
			/* not reached, but keep compiler quiet */
			return ACL_NO_RIGHTS;
	}
}


/* ****************************************************************
 * Exported routines for examining a user's privileges for various objects
 *
 * See aclmask() for a description of the common API for these functions.
 *
 * Note: we give lookup failure the full ereport treatment because the
 * has_xxx_privilege() family of functions allow users to pass any random
 * OID to these functions.
 * ****************************************************************
 */

/*
 * Exported routine for examining a user's privileges for a column
 *
 * Note: this considers only privileges granted specifically on the column.
 * It is caller's responsibility to take relation-level privileges into account
 * as appropriate.	(For the same reason, we have no special case for
 * superuser-ness here.)
 */
AclMode
pg_attribute_aclmask(Oid table_oid, AttrNumber attnum, Oid roleid,
					 AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	classTuple;
	HeapTuple	attTuple;
	Form_pg_class classForm;
	Form_pg_attribute attributeForm;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/*
	 * First, get the column's ACL from its pg_attribute entry
	 */
	attTuple = SearchSysCache2(ATTNUM,
							   ObjectIdGetDatum(table_oid),
							   Int16GetDatum(attnum));
	if (!HeapTupleIsValid(attTuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_COLUMN),
				 errmsg("attribute %d of relation with OID %u does not exist",
						attnum, table_oid)));
	attributeForm = (Form_pg_attribute) GETSTRUCT(attTuple);

	/* Throw error on dropped columns, too */
	if (attributeForm->attisdropped)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_COLUMN),
				 errmsg("attribute %d of relation with OID %u does not exist",
						attnum, table_oid)));

	aclDatum = SysCacheGetAttr(ATTNUM, attTuple, Anum_pg_attribute_attacl,
							   &isNull);

	/*
	 * Here we hard-wire knowledge that the default ACL for a column grants no
	 * privileges, so that we can fall out quickly in the very common case
	 * where attacl is null.
	 */
	if (isNull)
	{
		ReleaseSysCache(attTuple);
		return 0;
	}

	/*
	 * Must get the relation's ownerId from pg_class.  Since we already found
	 * a pg_attribute entry, the only likely reason for this to fail is that a
	 * concurrent DROP of the relation committed since then (which could only
	 * happen if we don't have lock on the relation).  We prefer to report "no
	 * privileges" rather than failing in such a case, so as to avoid unwanted
	 * failures in has_column_privilege() tests.
	 */
	classTuple = SearchSysCache1(RELOID, ObjectIdGetDatum(table_oid));
	if (!HeapTupleIsValid(classTuple))
	{
		ReleaseSysCache(attTuple);
		return 0;
	}
	classForm = (Form_pg_class) GETSTRUCT(classTuple);

	ownerId = classForm->relowner;

	ReleaseSysCache(classTuple);

	/* detoast column's ACL if necessary */
	acl = DatumGetAclP(aclDatum);

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(attTuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a table
 */
AclMode
pg_class_aclmask(Oid table_oid, Oid roleid,
				 AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Form_pg_class classForm;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/*
	 * Must get the relation's tuple from pg_class
	 */
	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(table_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_TABLE),
				 errmsg("relation with OID %u does not exist",
						table_oid)));
	classForm = (Form_pg_class) GETSTRUCT(tuple);

	/*
	 * Deny anyone permission to update a system catalog unless
	 * pg_authid.rolcatupdate is set.	(This is to let superusers protect
	 * themselves from themselves.)  Also allow it if allowSystemTableMods.
	 *
	 * As of 7.4 we have some updatable system views; those shouldn't be
	 * protected in this way.  Assume the view rules can take care of
	 * themselves.	ACL_USAGE is if we ever have system sequences.
	 */
	if ((mask & (ACL_INSERT | ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE | ACL_USAGE)) &&
		IsSystemClass(classForm) &&
		classForm->relkind != RELKIND_VIEW &&
		!has_rolcatupdate(roleid) &&
		!allowSystemTableMods)
	{
#ifdef ACLDEBUG
		elog(DEBUG2, "permission denied for system catalog update");
#endif
		mask &= ~(ACL_INSERT | ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE | ACL_USAGE);
	}

	/*
	 * Otherwise, superusers bypass all permission-checking.
	 */
	if (superuser_arg(roleid))
	{
#ifdef ACLDEBUG
		elog(DEBUG2, "OID %u is superuser, home free", roleid);
#endif
		ReleaseSysCache(tuple);
		return mask;
	}

	/*
	 * Normal case: get the relation's ACL from pg_class
	 */
	ownerId = classForm->relowner;

	aclDatum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relacl,
							   &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		switch (classForm->relkind)
		{
			case RELKIND_SEQUENCE:
				acl = acldefault(ACL_OBJECT_SEQUENCE, ownerId);
				break;
			default:
				acl = acldefault(ACL_OBJECT_RELATION, ownerId);
				break;
		}
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast rel's ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a database
 */
AclMode
pg_database_aclmask(Oid db_oid, Oid roleid,
					AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Get the database's ACL from pg_database
	 */
	tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(db_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_DATABASE),
				 errmsg("database with OID %u does not exist", db_oid)));

	ownerId = ((Form_pg_database) GETSTRUCT(tuple))->datdba;

	aclDatum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datacl,
							   &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_DATABASE, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a function
 */
AclMode
pg_proc_aclmask(Oid proc_oid, Oid roleid,
				AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Get the function's ACL from pg_proc
	 */
	tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(proc_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("function with OID %u does not exist", proc_oid)));

	ownerId = ((Form_pg_proc) GETSTRUCT(tuple))->proowner;

	aclDatum = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_proacl,
							   &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_FUNCTION, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a language
 */
AclMode
pg_language_aclmask(Oid lang_oid, Oid roleid,
					AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Get the language's ACL from pg_language
	 */
	tuple = SearchSysCache1(LANGOID, ObjectIdGetDatum(lang_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("language with OID %u does not exist", lang_oid)));

	ownerId = ((Form_pg_language) GETSTRUCT(tuple))->lanowner;

	aclDatum = SysCacheGetAttr(LANGOID, tuple, Anum_pg_language_lanacl,
							   &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_LANGUAGE, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a largeobject
 *
 * When a large object is opened for reading, it is opened relative to the
 * caller's snapshot, but when it is opened for writing, it is always relative
 * to SnapshotNow, as documented in doc/src/sgml/lobj.sgml.  This function
 * takes a snapshot argument so that the permissions check can be made relative
 * to the same snapshot that will be used to read the underlying data.
 */
AclMode
pg_largeobject_aclmask_snapshot(Oid lobj_oid, Oid roleid,
								AclMode mask, AclMaskHow how,
								Snapshot snapshot)
{
	AclMode		result;
	Relation	pg_lo_meta;
	ScanKeyData entry[1];
	SysScanDesc scan;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Get the largeobject's ACL from pg_language_metadata
	 */
	pg_lo_meta = heap_open(LargeObjectMetadataRelationId,
						   AccessShareLock);

	ScanKeyInit(&entry[0],
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(lobj_oid));

	scan = systable_beginscan(pg_lo_meta,
							  LargeObjectMetadataOidIndexId, true,
							  snapshot, 1, entry);

	tuple = systable_getnext(scan);
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("large object %u does not exist", lobj_oid)));

	ownerId = ((Form_pg_largeobject_metadata) GETSTRUCT(tuple))->lomowner;

	aclDatum = heap_getattr(tuple, Anum_pg_largeobject_metadata_lomacl,
							RelationGetDescr(pg_lo_meta), &isNull);

	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_LARGEOBJECT, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	systable_endscan(scan);

	heap_close(pg_lo_meta, AccessShareLock);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a namespace
 */
AclMode
pg_namespace_aclmask(Oid nsp_oid, Oid roleid,
					 AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * If we have been assigned this namespace as a temp namespace, check to
	 * make sure we have CREATE TEMP permission on the database, and if so act
	 * as though we have all standard (but not GRANT OPTION) permissions on
	 * the namespace.  If we don't have CREATE TEMP, act as though we have
	 * only USAGE (and not CREATE) rights.
	 *
	 * This may seem redundant given the check in InitTempTableNamespace, but
	 * it really isn't since current user ID may have changed since then. The
	 * upshot of this behavior is that a SECURITY DEFINER function can create
	 * temp tables that can then be accessed (if permission is granted) by
	 * code in the same session that doesn't have permissions to create temp
	 * tables.
	 *
	 * XXX Would it be safe to ereport a special error message as
	 * InitTempTableNamespace does?  Returning zero here means we'll get a
	 * generic "permission denied for schema pg_temp_N" message, which is not
	 * remarkably user-friendly.
	 */
	if (isTempNamespace(nsp_oid))
	{
		if (pg_database_aclcheck(MyDatabaseId, roleid,
								 ACL_CREATE_TEMP) == ACLCHECK_OK)
			return mask & ACL_ALL_RIGHTS_NAMESPACE;
		else
			return mask & ACL_USAGE;
	}

	/*
	 * Get the schema's ACL from pg_namespace
	 */
	tuple = SearchSysCache1(NAMESPACEOID, ObjectIdGetDatum(nsp_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_SCHEMA),
				 errmsg("schema with OID %u does not exist", nsp_oid)));

	ownerId = ((Form_pg_namespace) GETSTRUCT(tuple))->nspowner;

	aclDatum = SysCacheGetAttr(NAMESPACEOID, tuple, Anum_pg_namespace_nspacl,
							   &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_NAMESPACE, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a tablespace
 */
AclMode
pg_tablespace_aclmask(Oid spc_oid, Oid roleid,
					  AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Get the tablespace's ACL from pg_tablespace
	 */
	tuple = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(spc_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("tablespace with OID %u does not exist", spc_oid)));

	ownerId = ((Form_pg_tablespace) GETSTRUCT(tuple))->spcowner;

	aclDatum = SysCacheGetAttr(TABLESPACEOID, tuple,
							   Anum_pg_tablespace_spcacl,
							   &isNull);

	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_TABLESPACE, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a foreign
 * data wrapper
 */
AclMode
pg_foreign_data_wrapper_aclmask(Oid fdw_oid, Oid roleid,
								AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	Form_pg_foreign_data_wrapper fdwForm;

	/* Bypass permission checks for superusers */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Must get the FDW's tuple from pg_foreign_data_wrapper
	 */
	tuple = SearchSysCache1(FOREIGNDATAWRAPPEROID, ObjectIdGetDatum(fdw_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errmsg("foreign-data wrapper with OID %u does not exist",
						fdw_oid)));
	fdwForm = (Form_pg_foreign_data_wrapper) GETSTRUCT(tuple);

	/*
	 * Normal case: get the FDW's ACL from pg_foreign_data_wrapper
	 */
	ownerId = fdwForm->fdwowner;

	aclDatum = SysCacheGetAttr(FOREIGNDATAWRAPPEROID, tuple,
							   Anum_pg_foreign_data_wrapper_fdwacl, &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_FDW, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast rel's ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for examining a user's privileges for a foreign
 * server.
 */
AclMode
pg_foreign_server_aclmask(Oid srv_oid, Oid roleid,
						  AclMode mask, AclMaskHow how)
{
	AclMode		result;
	HeapTuple	tuple;
	Datum		aclDatum;
	bool		isNull;
	Acl		   *acl;
	Oid			ownerId;

	Form_pg_foreign_server srvForm;

	/* Bypass permission checks for superusers */
	if (superuser_arg(roleid))
		return mask;

	/*
	 * Must get the FDW's tuple from pg_foreign_data_wrapper
	 */
	tuple = SearchSysCache1(FOREIGNSERVEROID, ObjectIdGetDatum(srv_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errmsg("foreign server with OID %u does not exist",
						srv_oid)));
	srvForm = (Form_pg_foreign_server) GETSTRUCT(tuple);

	/*
	 * Normal case: get the foreign server's ACL from pg_foreign_server
	 */
	ownerId = srvForm->srvowner;

	aclDatum = SysCacheGetAttr(FOREIGNSERVEROID, tuple,
							   Anum_pg_foreign_server_srvacl, &isNull);
	if (isNull)
	{
		/* No ACL, so build default ACL */
		acl = acldefault(ACL_OBJECT_FOREIGN_SERVER, ownerId);
		aclDatum = (Datum) 0;
	}
	else
	{
		/* detoast rel's ACL if necessary */
		acl = DatumGetAclP(aclDatum);
	}

	result = aclmask(acl, roleid, ownerId, mask, how);

	/* if we have a detoasted copy, free it */
	if (acl && (Pointer) acl != DatumGetPointer(aclDatum))
		pfree(acl);

	ReleaseSysCache(tuple);

	return result;
}

/*
 * Exported routine for checking a user's access privileges to a column
 *
 * Returns ACLCHECK_OK if the user has any of the privileges identified by
 * 'mode'; otherwise returns a suitable error code (in practice, always
 * ACLCHECK_NO_PRIV).
 *
 * As with pg_attribute_aclmask, only privileges granted directly on the
 * column are considered here.
 */
AclResult
pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum,
					  Oid roleid, AclMode mode)
{
	if (pg_attribute_aclmask(table_oid, attnum, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to any/all columns
 *
 * If 'how' is ACLMASK_ANY, then returns ACLCHECK_OK if user has any of the
 * privileges identified by 'mode' on any non-dropped column in the relation;
 * otherwise returns a suitable error code (in practice, always
 * ACLCHECK_NO_PRIV).
 *
 * If 'how' is ACLMASK_ALL, then returns ACLCHECK_OK if user has any of the
 * privileges identified by 'mode' on each non-dropped column in the relation
 * (and there must be at least one such column); otherwise returns a suitable
 * error code (in practice, always ACLCHECK_NO_PRIV).
 *
 * As with pg_attribute_aclmask, only privileges granted directly on the
 * column(s) are considered here.
 *
 * Note: system columns are not considered here; there are cases where that
 * might be appropriate but there are also cases where it wouldn't.
 */
AclResult
pg_attribute_aclcheck_all(Oid table_oid, Oid roleid, AclMode mode,
						  AclMaskHow how)
{
	AclResult	result;
	HeapTuple	classTuple;
	Form_pg_class classForm;
	AttrNumber	nattrs;
	AttrNumber	curr_att;

	/*
	 * Must fetch pg_class row to check number of attributes.  As in
	 * pg_attribute_aclmask, we prefer to return "no privileges" instead of
	 * throwing an error if we get any unexpected lookup errors.
	 */
	classTuple = SearchSysCache1(RELOID, ObjectIdGetDatum(table_oid));
	if (!HeapTupleIsValid(classTuple))
		return ACLCHECK_NO_PRIV;
	classForm = (Form_pg_class) GETSTRUCT(classTuple);

	nattrs = classForm->relnatts;

	ReleaseSysCache(classTuple);

	/*
	 * Initialize result in case there are no non-dropped columns.	We want to
	 * report failure in such cases for either value of 'how'.
	 */
	result = ACLCHECK_NO_PRIV;

	for (curr_att = 1; curr_att <= nattrs; curr_att++)
	{
		HeapTuple	attTuple;
		AclMode		attmask;

		attTuple = SearchSysCache2(ATTNUM,
								   ObjectIdGetDatum(table_oid),
								   Int16GetDatum(curr_att));
		if (!HeapTupleIsValid(attTuple))
			continue;

		/* ignore dropped columns */
		if (((Form_pg_attribute) GETSTRUCT(attTuple))->attisdropped)
		{
			ReleaseSysCache(attTuple);
			continue;
		}

		/*
		 * Here we hard-wire knowledge that the default ACL for a column
		 * grants no privileges, so that we can fall out quickly in the very
		 * common case where attacl is null.
		 */
		if (heap_attisnull(attTuple, Anum_pg_attribute_attacl))
			attmask = 0;
		else
			attmask = pg_attribute_aclmask(table_oid, curr_att, roleid,
										   mode, ACLMASK_ANY);

		ReleaseSysCache(attTuple);

		if (attmask != 0)
		{
			result = ACLCHECK_OK;
			if (how == ACLMASK_ANY)
				break;			/* succeed on any success */
		}
		else
		{
			result = ACLCHECK_NO_PRIV;
			if (how == ACLMASK_ALL)
				break;			/* fail on any failure */
		}
	}

	return result;
}

/*
 * Exported routine for checking a user's access privileges to a table
 *
 * Returns ACLCHECK_OK if the user has any of the privileges identified by
 * 'mode'; otherwise returns a suitable error code (in practice, always
 * ACLCHECK_NO_PRIV).
 */
AclResult
pg_class_aclcheck(Oid table_oid, Oid roleid, AclMode mode)
{
	if (pg_class_aclmask(table_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a database
 */
AclResult
pg_database_aclcheck(Oid db_oid, Oid roleid, AclMode mode)
{
	if (pg_database_aclmask(db_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a function
 */
AclResult
pg_proc_aclcheck(Oid proc_oid, Oid roleid, AclMode mode)
{
	if (pg_proc_aclmask(proc_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a language
 */
AclResult
pg_language_aclcheck(Oid lang_oid, Oid roleid, AclMode mode)
{
	if (pg_language_aclmask(lang_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a largeobject
 */
AclResult
pg_largeobject_aclcheck_snapshot(Oid lobj_oid, Oid roleid, AclMode mode,
								 Snapshot snapshot)
{
	if (pg_largeobject_aclmask_snapshot(lobj_oid, roleid, mode,
										ACLMASK_ANY, snapshot) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a namespace
 */
AclResult
pg_namespace_aclcheck(Oid nsp_oid, Oid roleid, AclMode mode)
{
	if (pg_namespace_aclmask(nsp_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a tablespace
 */
AclResult
pg_tablespace_aclcheck(Oid spc_oid, Oid roleid, AclMode mode)
{
	if (pg_tablespace_aclmask(spc_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a foreign
 * data wrapper
 */
AclResult
pg_foreign_data_wrapper_aclcheck(Oid fdw_oid, Oid roleid, AclMode mode)
{
	if (pg_foreign_data_wrapper_aclmask(fdw_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Exported routine for checking a user's access privileges to a foreign
 * server
 */
AclResult
pg_foreign_server_aclcheck(Oid srv_oid, Oid roleid, AclMode mode)
{
	if (pg_foreign_server_aclmask(srv_oid, roleid, mode, ACLMASK_ANY) != 0)
		return ACLCHECK_OK;
	else
		return ACLCHECK_NO_PRIV;
}

/*
 * Ownership check for a relation (specified by OID).
 */
bool
pg_class_ownercheck(Oid class_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(class_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_TABLE),
				 errmsg("relation with OID %u does not exist", class_oid)));

	ownerId = ((Form_pg_class) GETSTRUCT(tuple))->relowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a type (specified by OID).
 */
bool
pg_type_ownercheck(Oid type_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type with OID %u does not exist", type_oid)));

	ownerId = ((Form_pg_type) GETSTRUCT(tuple))->typowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for an operator (specified by OID).
 */
bool
pg_oper_ownercheck(Oid oper_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(oper_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("operator with OID %u does not exist", oper_oid)));

	ownerId = ((Form_pg_operator) GETSTRUCT(tuple))->oprowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a function (specified by OID).
 */
bool
pg_proc_ownercheck(Oid proc_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(proc_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("function with OID %u does not exist", proc_oid)));

	ownerId = ((Form_pg_proc) GETSTRUCT(tuple))->proowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a procedural language (specified by OID)
 */
bool
pg_language_ownercheck(Oid lan_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(LANGOID, ObjectIdGetDatum(lan_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("language with OID %u does not exist", lan_oid)));

	ownerId = ((Form_pg_language) GETSTRUCT(tuple))->lanowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a largeobject (specified by OID)
 *
 * This is only used for operations like ALTER LARGE OBJECT that are always
 * relative to SnapshotNow.
 */
bool
pg_largeobject_ownercheck(Oid lobj_oid, Oid roleid)
{
	Relation	pg_lo_meta;
	ScanKeyData entry[1];
	SysScanDesc scan;
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	/* There's no syscache for pg_largeobject_metadata */
	pg_lo_meta = heap_open(LargeObjectMetadataRelationId,
						   AccessShareLock);

	ScanKeyInit(&entry[0],
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(lobj_oid));

	scan = systable_beginscan(pg_lo_meta,
							  LargeObjectMetadataOidIndexId, true,
							  SnapshotNow, 1, entry);

	tuple = systable_getnext(scan);
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("large object %u does not exist", lobj_oid)));

	ownerId = ((Form_pg_largeobject_metadata) GETSTRUCT(tuple))->lomowner;

	systable_endscan(scan);
	heap_close(pg_lo_meta, AccessShareLock);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a namespace (specified by OID).
 */
bool
pg_namespace_ownercheck(Oid nsp_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(NAMESPACEOID, ObjectIdGetDatum(nsp_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_SCHEMA),
				 errmsg("schema with OID %u does not exist", nsp_oid)));

	ownerId = ((Form_pg_namespace) GETSTRUCT(tuple))->nspowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a tablespace (specified by OID).
 */
bool
pg_tablespace_ownercheck(Oid spc_oid, Oid roleid)
{
	HeapTuple	spctuple;
	Oid			spcowner;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	/* Search syscache for pg_tablespace */
	spctuple = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(spc_oid));
	if (!HeapTupleIsValid(spctuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("tablespace with OID %u does not exist", spc_oid)));

	spcowner = ((Form_pg_tablespace) GETSTRUCT(spctuple))->spcowner;

	ReleaseSysCache(spctuple);

	return has_privs_of_role(roleid, spcowner);
}

/*
 * Ownership check for an operator class (specified by OID).
 */
bool
pg_opclass_ownercheck(Oid opc_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(CLAOID, ObjectIdGetDatum(opc_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("operator class with OID %u does not exist",
						opc_oid)));

	ownerId = ((Form_pg_opclass) GETSTRUCT(tuple))->opcowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for an operator family (specified by OID).
 */
bool
pg_opfamily_ownercheck(Oid opf_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opf_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("operator family with OID %u does not exist",
						opf_oid)));

	ownerId = ((Form_pg_opfamily) GETSTRUCT(tuple))->opfowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a text search dictionary (specified by OID).
 */
bool
pg_ts_dict_ownercheck(Oid dict_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dict_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("text search dictionary with OID %u does not exist",
						dict_oid)));

	ownerId = ((Form_pg_ts_dict) GETSTRUCT(tuple))->dictowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a text search configuration (specified by OID).
 */
bool
pg_ts_config_ownercheck(Oid cfg_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfg_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
			   errmsg("text search configuration with OID %u does not exist",
					  cfg_oid)));

	ownerId = ((Form_pg_ts_config) GETSTRUCT(tuple))->cfgowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a foreign-data wrapper (specified by OID).
 */
bool
pg_foreign_data_wrapper_ownercheck(Oid srv_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(FOREIGNDATAWRAPPEROID, ObjectIdGetDatum(srv_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("foreign-data wrapper with OID %u does not exist",
						srv_oid)));

	ownerId = ((Form_pg_foreign_data_wrapper) GETSTRUCT(tuple))->fdwowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a foreign server (specified by OID).
 */
bool
pg_foreign_server_ownercheck(Oid srv_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(FOREIGNSERVEROID, ObjectIdGetDatum(srv_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("foreign server with OID %u does not exist",
						srv_oid)));

	ownerId = ((Form_pg_foreign_server) GETSTRUCT(tuple))->srvowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a database (specified by OID).
 */
bool
pg_database_ownercheck(Oid db_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			dba;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(db_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_DATABASE),
				 errmsg("database with OID %u does not exist", db_oid)));

	dba = ((Form_pg_database) GETSTRUCT(tuple))->datdba;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, dba);
}

/*
 * Ownership check for a collation (specified by OID).
 */
bool
pg_collation_ownercheck(Oid coll_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(COLLOID, ObjectIdGetDatum(coll_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("collation with OID %u does not exist", coll_oid)));

	ownerId = ((Form_pg_collation) GETSTRUCT(tuple))->collowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for a conversion (specified by OID).
 */
bool
pg_conversion_ownercheck(Oid conv_oid, Oid roleid)
{
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	tuple = SearchSysCache1(CONVOID, ObjectIdGetDatum(conv_oid));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("conversion with OID %u does not exist", conv_oid)));

	ownerId = ((Form_pg_conversion) GETSTRUCT(tuple))->conowner;

	ReleaseSysCache(tuple);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Ownership check for an extension (specified by OID).
 */
bool
pg_extension_ownercheck(Oid ext_oid, Oid roleid)
{
	Relation	pg_extension;
	ScanKeyData entry[1];
	SysScanDesc scan;
	HeapTuple	tuple;
	Oid			ownerId;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	/* There's no syscache for pg_extension, so do it the hard way */
	pg_extension = heap_open(ExtensionRelationId, AccessShareLock);

	ScanKeyInit(&entry[0],
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(ext_oid));

	scan = systable_beginscan(pg_extension,
							  ExtensionOidIndexId, true,
							  SnapshotNow, 1, entry);

	tuple = systable_getnext(scan);
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("extension with OID %u does not exist", ext_oid)));

	ownerId = ((Form_pg_extension) GETSTRUCT(tuple))->extowner;

	systable_endscan(scan);
	heap_close(pg_extension, AccessShareLock);

	return has_privs_of_role(roleid, ownerId);
}

/*
 * Check whether specified role has CREATEROLE privilege (or is a superuser)
 *
 * Note: roles do not have owners per se; instead we use this test in
 * places where an ownership-like permissions test is needed for a role.
 * Be sure to apply it to the role trying to do the operation, not the
 * role being operated on!	Also note that this generally should not be
 * considered enough privilege if the target role is a superuser.
 * (We don't handle that consideration here because we want to give a
 * separate error message for such cases, so the caller has to deal with it.)
 */
bool
has_createrole_privilege(Oid roleid)
{
	bool		result = false;
	HeapTuple	utup;

	/* Superusers bypass all permission checking. */
	if (superuser_arg(roleid))
		return true;

	utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
	if (HeapTupleIsValid(utup))
	{
		result = ((Form_pg_authid) GETSTRUCT(utup))->rolcreaterole;
		ReleaseSysCache(utup);
	}
	return result;
}

/*
 * Fetch pg_default_acl entry for given role, namespace and object type
 * (object type must be given in pg_default_acl's encoding).
 * Returns NULL if no such entry.
 */
static Acl *
get_default_acl_internal(Oid roleId, Oid nsp_oid, char objtype)
{
	Acl		   *result = NULL;
	HeapTuple	tuple;

	tuple = SearchSysCache3(DEFACLROLENSPOBJ,
							ObjectIdGetDatum(roleId),
							ObjectIdGetDatum(nsp_oid),
							CharGetDatum(objtype));

	if (HeapTupleIsValid(tuple))
	{
		Datum		aclDatum;
		bool		isNull;

		aclDatum = SysCacheGetAttr(DEFACLROLENSPOBJ, tuple,
								   Anum_pg_default_acl_defaclacl,
								   &isNull);
		if (!isNull)
			result = DatumGetAclPCopy(aclDatum);
		ReleaseSysCache(tuple);
	}

	return result;
}

/*
 * Get default permissions for newly created object within given schema
 *
 * Returns NULL if built-in system defaults should be used
 */
Acl *
get_user_default_acl(GrantObjectType objtype, Oid ownerId, Oid nsp_oid)
{
	Acl		   *result;
	Acl		   *glob_acl;
	Acl		   *schema_acl;
	Acl		   *def_acl;
	char		defaclobjtype;

	/*
	 * Use NULL during bootstrap, since pg_default_acl probably isn't there
	 * yet.
	 */
	if (IsBootstrapProcessingMode())
		return NULL;

	/* Check if object type is supported in pg_default_acl */
	switch (objtype)
	{
		case ACL_OBJECT_RELATION:
			defaclobjtype = DEFACLOBJ_RELATION;
			break;

		case ACL_OBJECT_SEQUENCE:
			defaclobjtype = DEFACLOBJ_SEQUENCE;
			break;

		case ACL_OBJECT_FUNCTION:
			defaclobjtype = DEFACLOBJ_FUNCTION;
			break;

		default:
			return NULL;
	}

	/* Look up the relevant pg_default_acl entries */
	glob_acl = get_default_acl_internal(ownerId, InvalidOid, defaclobjtype);
	schema_acl = get_default_acl_internal(ownerId, nsp_oid, defaclobjtype);

	/* Quick out if neither entry exists */
	if (glob_acl == NULL && schema_acl == NULL)
		return NULL;

	/* We need to know the hard-wired default value, too */
	def_acl = acldefault(objtype, ownerId);

	/* If there's no global entry, substitute the hard-wired default */
	if (glob_acl == NULL)
		glob_acl = def_acl;

	/* Merge in any per-schema privileges */
	result = aclmerge(glob_acl, schema_acl, ownerId);

	/*
	 * For efficiency, we want to return NULL if the result equals default.
	 * This requires sorting both arrays to get an accurate comparison.
	 */
	aclitemsort(result);
	aclitemsort(def_acl);
	if (aclequal(result, def_acl))
		result = NULL;

	return result;
}
