When releasing the ERC-20 token, OZ(OpenZeppelin)'s util Context.sol is inherited.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
I read that when using a meta-transaction solution such as EIP-2771, Context.sol is useful. https://forum.openzeppelin.com/t/help-understanding-contract-context/10579
function _msgSender() internal view virtual override returns (address sender) {
if (isTrustedForwarder(msg.sender)) {
// The assembly code is more direct than the Solidity version using `abi.decode`.
assembly { sender := shr(96, calldataload(sub(calldatasize(), 20))) }
} else {
return super._msgSender();
}
}
But in the case of ERC-20, why shoud I use Context.sol's _msgSender()?
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
Doesn't make it more secure?
What is the usage of Context.sol within ERC-20?
Thank you in advance.
