solidity

• ethereum/solidity
• .sol
• 参考
  • https://binaries.soliditylang.org/
  • wikipedia Solidity
  • 开发: ganache, hardhat, solcjs
  • niftymints/contract-interface
  • Solidity by Example
  • cyrusadkisson/solidity-baby-steps
  • https://www.stateofthedapps.com/
• 智能合约 - 投票、众筹、拍卖、货币、NTF、DAO

# NPM
npm install -g solc

# solc by docker
docker run --rm -it ethereum/solc:stable solc --version
docker run --rm -it -v $PWD:/src ethereum/solc:stable -o /src/output --abi --bin /src/Contract.sol

# brew
brew install ethereum/ethereum/solidity

• solc
  • npm install -g solc
  • docker run ethereum/solc:stable
  • https://binaries.soliditylang.org/
    • ethereum/solc-bin
• remix online
  • https://github.com/ethereum/remix-live
  • https://remix.ethereum.org/

Syntax

unit	value
wei	1
gwei	1e9
ether	1e18

• 时间单位 seconds, minutes, hours, days, weeks
• block
  • basefee, chainid, coinbase, difficulty, gaslimit, number, timestamp
• gasleft() returns (uint256)
• blockhash(uint blockNumber) returns (bytes32)
• msg
  • data, sender, sig, value
• tx
  • gasprice, origin
• abi
  • decode, encode, encodePacked, encodeWithSelector, encodeWithSignature, encodeCall
• error
  • assert, require, revert
• math
  • addmod, mulmod, keccak256, sha256, ripemd160, ecrecover
• this - 当前合约地址
• selfdestruct(address payable recipient) - 销毁合约
• type(xyz)
  • name, creationCode, runtimeCode, interfaceId, min, max

---

• pragma
• import
• contract
• library
• interface
• 类型
  • bool - !,&&,||,==,!=
  • uint,int - <=,<,==,!=,>=,>, &,|,^,~, <<,>>, +,-.*./,%,**
    • type(int).{min,max} 类型最大最小值
    • 8,16,24,32,64,128,160,256
    • 8-256, step 8
    • uint,int -> uint256, int256
  • fixed, ufixed - MxN - M.N - 8 < M < 256, 0 < N < 80
  • address, address payable
    • bytes20, uint160
    • <address>
      • balance, code, codehash, call, delegatecall, staticcall
    • <address payable>
      • transfer
      • send
  • bytesN - 1 < N < 32
  • bytes - 动态数组
  • string - 数组
  • enum
  • valute type - type UFixed256x18 is uint256
  • modifier
    • pure,view,payable,immutable,anonymous,indexed,virtual,override
  • event
    • anonymous - 不存储事件签名作为 topic
    • indexed - 存储参数作为 topic
  • function
    • pure - 不能访问 state
    • view - 不能修改 state
    • payable - 可接受 ether
    • virtual - 可修改
    • override
    • 可见性
      • public, private, external, internal
    • <function>
      • address
      • selector
  • contract - 类似 class
  • 引用
    • memory, storage, calldata
  • mapping - 类似 map
    • key 使用 keccak256 计算 - 不存储 key 值
    • 没有长度，不能遍历
  • struct
  • delete xyz - 设置为初始值，可 删除数组/mapping 元素
• 变量
  • 状态变量 - 位于 storage
  • 本地变量
  • 全局变量
• 函数 - private, public, external, internal, view, pure
  • 默认 public
  • external 不能自己调用，只能给外部调用
    • 推荐使用
  • internal - 类似 protected
  • view - 只读
  • pure - 不读也不写状态变量
  • 支持自定义 modifier - 支持接受参数
    • _; 表示原始代码
• https://docs.soliditylang.org/en/latest/types.html
• https://docs.soliditylang.org/en/latest/units-and-global-variables.html

Interfaces

• Ownable, CloneFactory, ECR20

// EIP-1167
interface CloneFactory {
  function createClone(address target) internal returns (address result);

  function isClone(address target, address query) internal view returns (bool result);
}

FAQ

_;

modifier onlyOwner {
    if (msg.sender != owner) throw;
    _; // 原本的代码
}

例如

function setValue(uint256 _val) onlyOwner {
  value = _val;
}

变成

function setValue(uint256 _val) {
  if (msg.sender != owner) throw;
  value = _val;
}

• Condition-Orientated Programming

Stack too deep when compiling inline assembly

EVM 只有 16 slots, 尝试将 storage 移到 memory

或者设置 optimizer

const config: HardhatUserConfig = {
  solidity: {
    version: '0.8.4',
    settings: {
      optimizer: {
        runs: 200,
        enabled: true,
      },
    },
  },
};
export default config;

Type struct Moloch.Proposal is only valid in storage because it contains a (nested) mapping

struct 包含 mapping，不能使用 memory，使用 storage