aclchk.c

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/*-------------------------------------------------------------------------
 *
 * aclchk.c
 *    Routines to check access control permissions.
 *
 * Portions Copyright (c) 1996-2013, 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/htup_details.h"
#include "access/sysattr.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.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_event_trigger.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 "nodes/makefuncs.h"
#include "parser/parse_func.h"
#include "parser/parse_type.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/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 ExecGrant_Type(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;
        case ACL_KIND_EVENT_TRIGGER:
            elog(ERROR, "grantable rights not supported for event triggers");
            /* not reached, but keep compiler quiet */
            return ACL_NO_RIGHTS;
        case ACL_KIND_TYPE:
            whole_mask = ACL_ALL_RIGHTS_TYPE;
            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_DOMAIN:
            all_privileges = ACL_ALL_RIGHTS_TYPE;
            errormsg = gettext_noop("invalid privilege type %s for domain");
            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_TYPE:
            all_privileges = ACL_ALL_RIGHTS_TYPE;
            errormsg = gettext_noop("invalid privilege type %s for type");
            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_DOMAIN:
        case ACL_OBJECT_TYPE:
            ExecGrant_Type(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.
 *
 * XXX: This function doesn't take any sort of locks on the objects whose
 * names it looks up.  In the face of concurrent DDL, we might easily latch
 * onto an old version of an object, causing the GRANT or REVOKE statement
 * to fail.
 */
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, NoLock, 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_DOMAIN:
        case ACL_OBJECT_TYPE:
            foreach(cell, objnames)
            {
                List       *typname = (List *) lfirst(cell);
                Oid         oid;

                oid = typenameTypeId(NULL, makeTypeNameFromNameList(typname));
                objects = lappend_oid(objects, oid);
            }
            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, false);

        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_MATVIEW);
                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;
        case ACL_OBJECT_TYPE:
            all_privileges = ACL_ALL_RIGHTS_TYPE;
            errormsg = gettext_noop("invalid privilege type %s for type");
            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 do permissions checks */
        ListCell   *nspcell;

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

            /*
             * Note that we must do the permissions check against the target
             * role not the calling user.  We require CREATE privileges, since
             * without CREATE you won't be able to do anything using the
             * default privs anyway.
             */
            iacls->nspid = get_namespace_oid(nspname, false);

            aclresult = pg_namespace_aclcheck(iacls->nspid, iacls->roleid,
                                              ACL_CREATE);
            if (aclresult != ACLCHECK_OK)
                aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
                               nspname);

            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;

        case ACL_OBJECT_TYPE:
            objtype = DEFACLOBJ_TYPE;
            if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
                this_privileges = ACL_ALL_RIGHTS_TYPE;
            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, 0);
        }
    }
    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 (isNew)
            InvokeObjectPostCreateHook(DefaultAclRelationId,
                                       HeapTupleGetOid(newtuple), 0);
        else
            InvokeObjectPostAlterHook(DefaultAclRelationId,
                                      HeapTupleGetOid(newtuple), 0);
    }

    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;
            case DEFACLOBJ_TYPE:
                iacls.objtype = ACL_OBJECT_TYPE;
                break;
            default:
                /* Shouldn't get here */
                elog(ERROR, "unexpected default ACL type: %d",
                     (int) 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 TypeRelationId:
                istmt.objtype = ACL_OBJECT_TYPE;
                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 void
ExecGrant_Type(InternalGrant *istmt)
{
    Relation    relation;
    ListCell   *cell;

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

    relation = heap_open(TypeRelationId, RowExclusiveLock);

    foreach(cell, istmt->objects)
    {
        Oid         typId = lfirst_oid(cell);
        Form_pg_type pg_type_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_type];
        bool        nulls[Natts_pg_type];
        bool        replaces[Natts_pg_type];
        int         noldmembers;
        int         nnewmembers;
        Oid        *oldmembers;
        Oid        *newmembers;
        HeapTuple   tuple;

        /* Search syscache for pg_type */
        tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typId));
        if (!HeapTupleIsValid(tuple))
            elog(ERROR, "cache lookup failed for type %u", typId);

        pg_type_tuple = (Form_pg_type) GETSTRUCT(tuple);

        if (pg_type_tuple->typelem != 0 && pg_type_tuple->typlen == -1)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_GRANT_OPERATION),
                     errmsg("cannot set privileges of array types"),
                errhint("Set the privileges of the element type instead.")));

        /* Used GRANT DOMAIN on a non-domain? */
        if (istmt->objtype == ACL_OBJECT_DOMAIN &&
            pg_type_tuple->typtype != TYPTYPE_DOMAIN)
            ereport(ERROR,
                    (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                     errmsg("\"%s\" is not a domain",
                            NameStr(pg_type_tuple->typname))));

        /*
         * Get owner ID and working copy of existing ACL. If there's no ACL,
         * substitute the proper default.
         */
        ownerId = pg_type_tuple->typowner;
        aclDatum = heap_getattr(tuple, Anum_pg_type_typacl,
                                RelationGetDescr(relation), &isNull);
        if (isNull)
        {
            old_acl = acldefault(istmt->objtype, 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,
                                     typId, grantorId, ACL_KIND_TYPE,
                                     NameStr(pg_type_tuple->typname),
                                     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_type_typacl - 1] = true;
        values[Anum_pg_type_typacl - 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(TypeRelationId, typId, 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_EVENT_TRIGGER */
    gettext_noop("permission denied for event trigger %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_EVENT_TRIGGER */
    gettext_noop("must be owner of event trigger %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;
    }
}


/*
 * Special common handling for types: use element type instead of array type,
 * and format nicely
 */
void
aclcheck_error_type(AclResult aclerr, Oid typeOid)
{
    Oid element_type = get_element_type(typeOid);

    aclcheck_error(aclerr, ACL_KIND_TYPE, format_type_be(element_type ? element_type : typeOid));
}


/* 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);
        case ACL_KIND_EVENT_TRIGGER:
            elog(ERROR, "grantable rights not supported for event triggers");
            /* not reached, but keep compiler quiet */
            return ACL_NO_RIGHTS;
        case ACL_KIND_TYPE:
            return pg_type_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 examining a user's privileges for a type.
 */
AclMode
pg_type_aclmask(Oid type_oid, Oid roleid, AclMode mask, AclMaskHow how)
{
    AclMode     result;
    HeapTuple   tuple;
    Datum       aclDatum;
    bool        isNull;
    Acl        *acl;
    Oid         ownerId;

    Form_pg_type typeForm;

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

    /*
     * Must get the type's tuple from pg_type
     */
    tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type_oid));
    if (!HeapTupleIsValid(tuple))
        ereport(ERROR,
                (errmsg("type with OID %u does not exist",
                        type_oid)));
    typeForm = (Form_pg_type) GETSTRUCT(tuple);

    /* "True" array types don't manage permissions of their own */
    if (typeForm->typelem != 0 && typeForm->typlen == -1)
    {
        Oid         elttype_oid = typeForm->typelem;

        ReleaseSysCache(tuple);

        tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(elttype_oid));
        if (!HeapTupleIsValid(tuple))
            ereport(ERROR,
                    (errmsg("type with OID %u does not exist",
                            type_oid)));
        typeForm = (Form_pg_type) GETSTRUCT(tuple);
    }

    /*
     * Normal case: get the type's ACL from pg_type
     */
    ownerId = typeForm->typowner;

    aclDatum = SysCacheGetAttr(TYPEOID, tuple,
                               Anum_pg_type_typacl, &isNull);
    if (isNull)
    {
        /* No ACL, so build default ACL */
        acl = acldefault(ACL_OBJECT_TYPE, 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;
}

/*
 * Exported routine for checking a user's access privileges to a type
 */
AclResult
pg_type_aclcheck(Oid type_oid, Oid roleid, AclMode mode)
{
    if (pg_type_aclmask(type_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 an event trigger (specified by OID).
 */
bool
pg_event_trigger_ownercheck(Oid et_oid, Oid roleid)
{
    HeapTuple   tuple;
    Oid         ownerId;

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

    tuple = SearchSysCache1(EVENTTRIGGEROID, ObjectIdGetDatum(et_oid));
    if (!HeapTupleIsValid(tuple))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("event trigger with OID %u does not exist",
                        et_oid)));

    ownerId = ((Form_pg_event_trigger) GETSTRUCT(tuple))->evtowner;

    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;

        case ACL_OBJECT_TYPE:
            defaclobjtype = DEFACLOBJ_TYPE;
            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;
}