Ethereum: Invalid Opcode Error on Arbitrum and Binance Smart Chain
As a developer of Ethereum-based dApps, you have probably encountered issues when using smart contracts deployed on both Binance Smart Chain (BSC) and Arbitrum. One such issue that has plagued developers is the “Invalid Opcode” error that can occur when using proxy contracts on these networks.
In this article, we will explore what the “Invalid Opcode” error is, how it is caused by invalid opcodes, and provide guidance on troubleshooting and resolving issues in your BSC and ARB projects.
What is an Invalid Opcode Error?
The “Invalid Opcode” error occurs when a contract attempts to call an opcode that does not exist. This can be caused by a number of reasons, including:
- Incorrectly defined operation codes
- Non-existent opcodes or functions are called
- Out-of-range arguments are passed
With proxy contracts, this error often occurs when using Ethereum Virtual Machine (EVM) bytecode generated by the proxy contract.
Causes of BSC invalid opcode error
Errors caused by invalid operation codes on Binance Smart Chain (BSC) can be caused by a number of factors:
- Invalid operation codes: If a contract defines an operation code that is not in the EVM, it will return an invalid operation code.
- Non-existent operation codes or functions: If a proxy contract calls an operation code or function that is not defined in its bytecode, it will return an invalid opcode error.
Arbitrum Invalid Opcode Error Causes
In Arbitrum, errors caused by invalid opcodes can be caused by the following:
- Invalid Opcodes: Similar to BSC, invalid opcodes can result in an “Invalid Opcode” error.
- Out-of-Range Arguments: Passing an argument that is outside the valid range of a given opcode or function call will result in an invalid opcode.
Troubleshooting Steps
To resolve invalid opcode errors in BSC and Arbitrum, follow these troubleshooting steps:
1. Check the contract code
Before deploying a contract to a BSC or ARB, check its source code to ensure that all opcodes are defined correctly and that they are not missing any essential functionality.
2. Check for non-existent opcodes
Before deploying, ensure that the contract defines all required opcodes and functions.
3. Check the argument range
Ensure that the argument ranges of the opcode calls match the expected range. For example, if the opcode requires a specific value type (e.g. uint256), ensure that the contract bytecode includes this function call with the correct arguments.
4. Use an Ethers.js or Web3 library
When using smart contracts, consider using libraries like Ethers.js or Web3 to validate and clean up your code before deploying. These libraries provide features such as:
- Code Validation: Checks for syntax errors and invalid operation codes
- Argument Sanitization: Ensures that arguments are in valid ranges
5. Log Errors
When you encounter an “Invalid Opcode” error, log it using a logging library such as ethers.js or Web3’s console. This will help you diagnose the issue more effectively.
Conclusion
Invalid opcode errors can be frustrating when working with Ethereum-based dApps, but they are relatively easy to resolve with the right debugging tools and knowledge of the EVM bytecode. By following these troubleshooting steps, developers can identify and fix issues that cause invalid opcodes in their BSC and ARB projects.
Stay up to date with Ethereum and smart contract developments by following reputable sources such as the Ethereum Foundation, Web3.org, and DappRadar.com.
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Additional Resources
- Ethers.js: A library for interacting with Ethereum smart contracts.
- Web3.js: A JavaScript library for interacting with the Ethereum blockchain.