第2节：合约部署

Reversing and debugging EVM Smart contracts: Deployment of a smart contract-part2

无payable

pragma solidity ^0.8.0;  
contract Test {      
    uint balance;      
    constructor() {         
        balance = 9;     
    } 
}

EVM中，存储相关一共有三个区域：

1. stack
2. memory
3. storage

在执行构造函数之前，依然会做前置校验：msg.value等

涉及到构造函数的部分，主要是使用了SSTORE，将balance = 9存储到storage中，然后退出

中间比较含糊的是memory的地址问题，需要进一步理解（先忽略）

有payable

pragma solidity ^0.8.0;  
contract Test {      
    uint balance;      
    constructor() payable {         
        balance = 9;     
    } 
}

1. opcode中，缺少了对msg.value校验对逻辑，因为已经不需要限定为0了
2. 所以加上payable后opcode对size变小了，部署需要的gas也变少了

增加参数

pragma solidity ^0.8.0;  
    contract Test {       
        uint balance;      
        constructor(uint a,uint b) payable { 
            balance = 9;     
    } 
}

• 配合使用CODESIZE, CODECOPY, 将参数拷贝到内存中；（1，2）
• data字段是bytecode，evm会按照逻辑解析，并执行bytecode，这是指令
• 验证参数个数，确定是2个，否则revert

总结

1. It stores the free memory pointer as every smart contract does.
2. It copies the 2 arguments provided by transaction data and store them to memory.
3. It verifies that we entered at least 2 arguments in the constructor. (not less)
4. It copies the 2 arguments in memory in to the stack.
5. It executes the constructor by setting balance to 9.
6. It copies the code into memory and stop the execution.

Tips

• Every solidity smart contracts starts by mstore(0x40,0x80), which is 0x6080604052 in hex.