When I decoded and checked a transaction's log about the polygon contract (0x0000000000000000000000000000000000001010), I found the signature like "LogFeeTransfer(address,address,address,uint256,uint256,uint256,uint256,uint256)".
However I can't find that polygon contract emits this event.
What's this event for and where is used in the contract?
Thank you.
I searched the contract source code on polygonscan for "emit LogFeeContract".
This address on Polygon most likely holds a precompiled contract - which is usually not written in Solidity but in language of the client software (Golang, JS, ...).
My guess is that it's just a Solidity representation of the original Golang (or any other) code, so that it doesn't confuse users that there is no contract on this address on PolygonScan even though this address is publicly known as the native token address.
The Golang implementation can also emit events, as it's literally part of the node client software.
I wasn't able to find any specific implementation in other language apart from Solidity, but my answer is based on the fact that the
...1010address is within the range of reserved addresses for precompiled contracts on Ethereum - https://eips.ethereum.org/EIPS/eip-1352. Even though Polygon might technically ignore this EIP.More info on precompiles: https://ethereum.stackexchange.com/search?q=precompiled