How to automatically identify which value is stored in specific location of transaction input , given a smart contract source code and ABI?

Question

For example, a function's name and parameters are given as following:

function batchTransfer(address[] _receivers, uint256 _value) public returns (bool);

Then I want to get a python dictionary whose key is the first location of the value in transaction input, and value is the corresponding value, for example:

p {};

p["0"] = 0x34672534; // the function signature

p["4"] = 'offset'; // the offset of '_receivers' value

p["36"] = '_value';

p["4+offset"] = '_receivers.length'; // the length of '_receivers'

p["4+offset+1*32"] = '_receivers[1]'

p["4+offset+2*32"] = '_receivers[2]'

Note: since when reaching this stage, only contract source codes and ABI were given, and there are no concrete inputs, namely, I should derive this dictionary by statically analyzing source codes or ABI, so the location can be expressed by expressions as shown above.

So, is there any way to implement such a parser to get this map?

Or is there already an existing one?

Answer 1

One way is to use this https://github.com/ConsenSys/abi-decoder or even better https://web3js.readthedocs.io/en/v1.2.0/web3-eth-abi.html#decodeparameters