mirror of https://github.com/status-im/EIPs.git
48 lines
1.9 KiB
Markdown
48 lines
1.9 KiB
Markdown
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## Preamble
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EIP: <to be assigned>
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Title: REVERT instruction in the Ethereum Virtual Machine
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Author: Alex Beregszaszi, Nikolai Mushegian (nikolai@nexusdev.us)
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Type: Standard Track
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Category: Core
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Status: Draft
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Created: 2017-02-06
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## Simple Summary
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The `REVERT` instruction provides a way to stop execution and revert state changes, without consuming all provided gas and with the ability to return a reason.
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## Abstract
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The `REVERT` instruction will stop execution, roll back all state changes done so far and provide a pointer to a memory section, which can be interpreted as an error code or message. While doing so, it will not consume all the remaining gas.
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## Motivation
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Currently this is not possible. There are two practical ways to revert a transaction from within a contract: running out of gas or executing an invalid instruction. Both of these options will consume all remaining gas. Additionally, reverting a transaction means that all changes, including LOGs, are lost and there is no way to convey a reason for aborting a transaction.
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## Specification
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The `REVERT` instruction is introduced at `0xfd`. Execution is aborted and state changes are rolled back.
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It expects two stack items, the top item is the `memory_length` followed by `memory_offset`. Both of these can equal to zero. The cost of the `REVERT` instruction equals to that of the `RETURN` instruction.
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In case there is not enough gas left to cover the cost of `REVERT` or there is a stack underflow, the effect of the `REVERT` instruction will equal to that of a regular out of gas exception.
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The content of the optionally provided memory section is not defined by this EIP, but is a candidate for another Informational EIP.
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## Rationale
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TBD
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## Backwards Compatibility
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This change has no effect on contracts created in the past.
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## Test Cases
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TBA
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## Copyright
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Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).
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