Pretty print control flow of Etherium debug traces

traceprint.ts

const fs = require('fs')
const chalk = require('chalk')

const trace = JSON.parse(fs.readFileSync('2019_08_09_mike_fail.json'))
const logs = trace.result.structLogs as TraceLog[]

interface TraceLog {
    depth: number
    error: string
    gas: number,
    gasCost: number,
    memory: string[],
    op: string,
    pc: number,
    stack: string[],
    storage: Record<string, string>
    address: string
    targetAddress: string,
    callDepth: number
}

function targetAddress(log: TraceLog) : string {
    return log.stack[log.stack.length - 2].replace(/^000000000000000000000000/, '')
}
function callArgs(log: TraceLog) : string {
    if(log.op == "DELEGATECALL"){
        const start = parseInt(log.stack[log.stack.length - 3], 16)
        const length = parseInt(log.stack[log.stack.length - 4], 16)
        return getMemory(log, start, length)
    } else {
        const start = parseInt(log.stack[log.stack.length - 4], 16)
        const length = parseInt(log.stack[log.stack.length - 5], 16)
        return getMemory(log, start, length)
    }
}

function getMemory(log: TraceLog, start: number, length: number): string {
    let out : string[] = []
    let remaining = length
    let slot = Math.floor(start / 32)
    let offset = start - slot * 32
    // console.log('READ', start, length, remaining, slot, offset)
    while(remaining > 0){
        const slotLen = Math.min(32 - offset, remaining)
        remaining -= slotLen
        // console.log('Slot',slot, offset, 'To read', slotLen, remaining)
        if(log.memory[slot] == undefined){
            console.log("READ PAST SLOT")
            break
        }
        out.push(log.memory[slot].substr(offset * 2, slotLen * 2))
        offset = 0
        slot += 1
    }
    return out.join("")
}

// Build contract address flow

let currentAddress: string = 'START'
const contractAddressStack: string[] = [currentAddress]
logs.forEach(log => {
    log.address = currentAddress
    log.callDepth = contractAddressStack.length
    if (log.op == "CREATE" || log.op == "CREATE2" ) {
        currentAddress = 'NEW'
        contractAddressStack.push(currentAddress)
    }
    if (log.op == "DELEGATECALL" || log.op == "STATICCALL" || log.op == "CALL" || log.op == "CALLCODE") {
        currentAddress = targetAddress(log)
        contractAddressStack.push(currentAddress)
    }
    if (log.op == "RETURN" || log.op == "REVERT") {
        currentAddress = contractAddressStack.pop() as string
    }

    if (log.op == "CALL" || log.op == "CALLCODE" || log.op == "RETURN" || log.op == "DELEGATECALL" || log.op == "STATICCALL" || log.op == "REVERT") {
        // console.log(log)
    }
    // console.log(log.pc, log.op)
})

// console.log(logs[0])

logs.forEach(log => {
    if (log.op == "DELEGATECALL" || log.op == "STATICCALL" || log.op == "CALL" || log.op == "CALLCODE") {
        const target = targetAddress(log)
        const args = callArgs(log)
        let methodSig = "?"
        if(args.length > 0){
            methodSig = args.substr(0,8)
        }
        console.log(chalk.red(log.op), target, methodSig)
    }
    if (log.op == "RETURN" || log.op == "REVERT") {
        console.log(chalk.red(log.op) )
    }
    console.log(`${log.pc}\t${log.op} ${chalk.blue(log.gas)}`)
})

console.log('----')
console.log(contractAddressStack)
logs.forEach(log => {
    if (log.op == "CREATE" || log.op == "CREATE2"){
        console.log(`${chalk.red(log.op)} ${chalk.blue(log.gas)}` )
    }
    const openingSpace = '  '.repeat(log.callDepth)
    if (log.op == "DELEGATECALL" || log.op == "STATICCALL" || log.op == "CALL" || log.op == "CALLCODE") {
        const target = targetAddress(log)
        const args = callArgs(log)
        let methodSig = "?"
        if(args.length > 0){
            methodSig = args.substr(0,8)
        }
        console.log(`${openingSpace}${chalk.red(log.op)} ${target} ${methodSig} ${chalk.blue(log.gas)}\n${openingSpace}${chalk.grey(args)}`)
    }
    if (log.op == "RETURN" || log.op == "REVERT") {
        console.log(`${openingSpace}${chalk.red(log.op)} ${chalk.blue(log.gas)}` )
    }
    //console.log(log)
})

// curl 'https://www.4byte.directory/api/v1/signatures/?hex_signature=095ea7b3'