---
eip: 2937
title: SET_INDESTRUCTIBLE opcode
author: Vitalik Buterin (@vbuterin)
discussions-to: https://ethereum-magicians.org/t/eip-2937-set-indestructible/4571
status: Stagnant
type: Standards Track
category: Core
created: 2020-09-04
---

## Simple Summary

Add a `SET_INDESTRUCTIBLE (0xA8)` opcode that prevents the contract from calling `SELFDESTRUCT (0xFF)`.

## Abstract

## Motivation

The intended use case would be for contracts to make their first byte of code be the `SET_INDESTRUCTIBLE` opcode if they wish to serve as libraries that guarantee to users that their code will exist unmodified forever. This is useful in account abstraction as well as other contexts.

Unlike EIPs that disable the `SELFDESTRUCT` opcode entirely, this EIP does not modify behavior of any existing contracts.

## Specification

Add a transaction-wide global variable `globals.indestructible: Set[Address]` (i.e. a variable that operates the same way as the selfdestructs set), initialized to the empty set.

Add a `SET_INDESTRUCTIBLE` opcode at `0xA8`, with gas cost `G_base`, that adds the current `callee` to the `globals.indestructible` set. If in the current execution context the `callee` is in `globals.indestructible`, the `SELFDESTRUCT` opcode throws an exception.

## Rationale

Alternative proposals to this include:

* Simply banning `SELFDESTRUCT` outright. This would be ideal, but has larger backwards compatibility issues.
* Using a local variable instead of a global variable. This is problematic because it would be broken by `DELEGATECALL`.

## Backwards Compatibility

TBD

## Security Considerations

This breaks forward compatibility with _some_ forms of state rent, which would simply delete contracts that get too old without paying some maintenance fee. However, this is not the case with all state size control schemes; for example this is not an issue if we use [ReGenesis](https://ledgerwatch.github.io/regenesis_plan.html).

If `SELFDESTRUCT` is ever removed in the future, this EIP would simply become a no-op.

## Copyright
Copyright and related rights waived via [CC0](../LICENSE.md).