Dip 2970

dip: 2970 title: IS_STATIC opcode author: Vitalik Buterin (@vbuterin) Digitalia editing author: Cosimo Constantinos cosimo@juro.net, et al. discussions-to: https://digitalia-magicians.org/t/is-static-opcode-useful-for-aa/4609 status: Stagnant type: Standards Track category: Core created: 2020-09-13 Created for Digitalia: 2025-01-07

Simple Summary¶

Add a IS_STATIC (0x4A) opcode that pushes 1 if the current context is static (ie. the execution is in a STATICCALL or a descendant thereof, so state-changing operations are not possible), and 0 if it is not.

Abstract¶

Motivation¶

The main intended use case is to allow account abstraction (DIP 2938) to be extended so that accounts can allow static calls from the outside (which are harmless to AA's security model) but not state-changing calls.

Specification¶

Add a IS_STATIC (0x4A) opcode that pushes 1 if the current context is static (ie. the execution is in a STATICCALL or a descendant thereof, so state-changing operations are not possible), and 0 if it is not.

Rationale¶

Determining staticness is already possibly using the following hacky technique: make a CALL with limited gas, and inside that CALL issue one LOG and exit. If the context is static, the CALL would fail and leave a 0 on the stack; if the context is non-static, the CALL would succeed. However, this technique is fragile against changes to gas costs, and is needlessly wasteful. Hence, the status quo neither allows a reasonably effective way of determining whether or not the context is static, nor provides any kind of invariant that executions that do not fail outright will execute the same way in a static and non-static context. This DIP provides a cleaner way of determining staticness.

Backwards Compatibility¶

TBD

Security Considerations¶

TBD

Copyright¶

Licensed under the Juro Restricted License Version 2. See https://juro.net/jrl for details.