Profiles gas consumption of a transaction line-by-line.
Uses debug_traceTransaction, for which geth must run with --rpcapi debug,eth flag. Note that ganache supports this API but the return is different from geth, which I suspect is a bug and will examine further later. Currently does not work with ganache.
Requires sourcemap, which is produced by solc --combined-json srcmap-runtime.
Command line:
node profile.js <RPC endpoint> <tx hash> <.sol file path> <sourcemap file path>
Sample output for profiling foo(10):
Gas used by transaction: 183443
0 pragma solidity ^0.4.24;
0
0 contract Bar {
0 uint s;
0
0 function bar (uint i) public returns (uint) {
0 s = s + i;
0 return s;
0 }
0 }
0
84 contract Foo {
0 uint s;
0 Bar bar;
0
0 constructor (address a) public {
0 bar = Bar(a);
0 }
0
89 function foo (uint c) public {
598 for (uint i=0; i<c; i++ ) {
155069 s = bar.bar(i);
0 }
0
226 if (s > 1) {
5233 s += 1;
0 }
0 }
0 }
0
synthetic instruction gas 680