I am had successfully deploy a flashloan contract on both Aurora & Aurora+ network (an EVM on Near protocol).

and also successfully tested with its RPC on hardhat, there are no issues, able to borrow and return fund.

However, when executing on mainnet, it shows a failed transaction with the following error: "A status code indicating if the top-level call succeeded or failed (applicable for Post BYZANTIUM blocks only).

what could be the possible root cause?

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.16;


contract Calc {

    function multiply(int ui) public returns (int) {

        return ui;
    }
}

After deploying this contract, I call the multiply method: near call name_contract.testnet multiply '{"ui": 16}' --accountId name_contract.testnet

I get result: '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10'

Ideally, the expected result should be: 16

But if you change the code as follows:

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.16;


contract Calc {

    address public owner;
    uint256 public num;


    function multiply(int ui) public returns (int) {

        return ui;
    }
}

I get result: Empty result ''

Expected result: 16

Using command ./evm2near my_contract.sol -o my_contract.wasm -b near, I get the following error: Failed to compile Solidity ABI: unexpected output from `solc'

I was able to figure out that this error occurs if the contract uses a constructor, example:

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.16;

contract Calc {

    address public owner;
    uint256 public num;

    constructor() {
        owner = msg.sender;
        num = 0;
    }

    function multiply(int a, int b) public pure returns (int) {
        return a * b;
    }
}

This error also occurs if events are used in the contract, example:

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.16;

contract Calc {

    address public owner;
    uint256 public num;

    event Multiply(uint256 mul);

    function multiply(uint256 a, uint256 b) public returns (uint256) {

        uint256 c = a * b;

        emit Multiply(c);

        return c;
    }
}

This allows nice output when calling from the NEAR CLI. Example:

$ near --networkId testnet --accountId birchmd.testnet call dev-1663014663747-27418521013742 multiply '{"a": 7, "b": 6}'

Scheduling a call: dev-1663014663747-27418521013742.multiply({"a": 7, "b": 6})
Doing account.functionCall()
Transaction Id 97g3DMfcZMyipJ5QLzRw46d6SvnjsTdyn1B1ZVH5w7fg
To see the transaction in the transaction explorer, please open this url in your browser
https://explorer.testnet.near.org/transactions/97g3DMfcZMyipJ5QLzRw46d6SvnjsTdyn1B1ZVH5w7fg
{ output: 42, status: 'SUCCESS' }

This feature is implemented by having environment functions like value_return and revert only update the internal EVM state (setting the exit status and return data), not call any external exit methods (like process::exit, or NEAR's host functions). Instead, the exit calls happen as part of a new function called post_exec. This gives a chance for the return data to be re-encoded from ABI into JSON before the value is returned.

The main files to focus on in the review are: compiler.rs, api.rs and encode.rs. Note that the code for decoding JSON into ABI input was simply moved from api.rs to decode.rs with no changes.

This script automatically compile compiler, then compile test contracts, deploy them in testchain, call some functions and check that they return correct results.

New tests can be added very easy, just add following string in All() function:

TestOne(File.sol, method, args, expected_result)

TODO : link this script to github actions (a bit difficult because it need some setup script)

// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.16;

contract Calc {

    address public owner;
    uint256 public num;


    function multiply(address addr) public returns (address) {

        return addr;
    }
}

The contract can be deployed, but when I call the multiply method: near call name_contract.testnet multiply '{"addr": "account1.testnet"}' --accountId name_contract.testnet

I get an error: Error: {"index":0,"kind":{"ExecutionError":"WebAssembly trap: An unreachable opcode was executed."}}

After the call: near call name_contract.testnet multiply '{"addr": "account1.testnet"}' --accountId name_contract.testnet I expect to be returned the account passed in the function parameter: account1.testnet