Ethereum: Invalid Opcode Error in Arbitrum and Binance Smart Chain
As a developer working on Ethereum-based dApps, you have probably encountered issues interacting with smart contracts implemented on both Binance Smart Chain (BSC) and Arbitrum. One such issue that plagues 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 guidelines on how to troubleshoot and resolve issues in your BSC and ARB projects.
What is an invalid opcode error?
The “Invalid Opcode” error occurs when a contract attempts to invoke a non-existent opcode. This can occur for several reasons, including:
- Incorrectly defined opcodes
- Invoking non-existent opcodes or functions
- Passing out-of-range arguments
In the context of proxy contracts, this error often occurs when using Ethereum Virtual Machine (EVM) bytecode generated by the proxy contract.
Causes of BSC Invalid Opcode Error
Binance Smart Chain (BSC) errors caused by invalid opcodes can be attributed to several factors:
- Invalid Opcodes: If a contract defines an opcode that does not exist in the EVM, an “Invalid Opcode” error will be displayed.
- Non-existent Opcodes or Functions
: If a proxy contract calls an opcode or function that is not defined in its bytecode, an “Invalid Opcode” error will be displayed.
Causes of Invalid Opcode Error in Arbitrum
Arbitrum errors caused by invalid opcodes can be categorized as:
- Invalid Opcodes: As with BSC, invalid opcodes can cause an “Invalid Opcode” error.
- Arguments Out of Range: Passing an argument that is outside the valid range for a given opcode or function call will result in an “Invalid Opcode” error.
Troubleshooting Steps
To resolve invalid opcode errors in BSC and Arbitrum, perform the following troubleshooting steps:
1. Review the Contract Code
Before implementing a contract with BSC or ARB, review its source code to ensure that all opcodes are properly defined and that no critical functionality is missing.
2. Check for opcodes
Before deploying, verify that all required opcodes and functions are defined in the contract.
3. Check the argument range
Make sure 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), verify that the contract bytecode includes this function call with the correct arguments.
4. Use an Ethers.js or Web3 library
When interacting with smart contracts, consider using libraries such as 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 opcodes
- Argument Sanitization: Ensures that arguments are within the correct ranges
5. Log Errors
When you encounter an “Invalid Opcode” error, log it using a logging library such as ethers.js or Web3 Console. This will help you diagnose the problem more effectively.
Conclusion
Invalid opcode errors can be frustrating when working with Ethereum-based dApps, but they are relatively easy to fix with the right debugging tools and knowledge of the EVM bytecode. By following these troubleshooting steps, developers can identify and resolve issues that are causing invalid opcodes in their BSC and ARB projects.
Stay up-to-date on the latest Ethereum developments and smart contract development by following trusted sources such as the Ethereum Foundation, Web3.org, and DappRadar.com.
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Additional Resources
- Ethers.js: A library for interfacing with Ethereum smart contracts.
- Web3.js: A JavaScript library for interfacing with the Ethereum blockchain.
