dyld dependency tree walker

gistfile1.txt

#!/usr/bin/env node

import macho from 'macho'
import * as path from 'path'
import * as fs from 'fs'

const rootExe = path.resolve(process.argv[2])

function resolve(exe, rpath, lib) {
  return path.resolve(lib.replace(/@rpath/, rpath).replace(/@loader_path/, path.dirname(exe)).replace(/@executable_path/, path.dirname(rootExe)))
}

function readLib(exe) {
  // Use https://lapcatsoftware.com/articles/bigsur.html to extract the dyld
  // cache
  if (!fs.existsSync(exe))
    return fs.readFileSync('/users/jeremy.rose/Desktop/libraries/' + exe)
  return fs.readFileSync(exe)
}

const getReexportDylibName = c => /^.*?(?=\x00)/.exec(c.data.slice(16).toString('utf8'))[0]

const seen = new Set
function printLibs(exe, depth=0, labels=null) {
  if (seen.has(exe)) return
  seen.add(exe)
  try {
    const {cmds} = macho.parse(readLib(exe))
    console.log('  '.repeat(depth) + exe + (labels ? ` [${labels.join(',')}]` : ''))
    const rpath = cmds.find(c => c.type === 'rpath')?.name
    const libs = []
    for (const cmd of cmds) {
      if (cmd.type === 'load_dylib')
        libs.push({name: cmd.name})
      else if (cmd.type === 'load_weak_dylib')
        libs.push({name: cmd.name, labels: ['weak']})
      else if (cmd.type === 'reexport_dylib')
        libs.push({name: getReexportDylibName(cmd), labels: ['reexported']})
    }
    for (const lib of libs) {
      printLibs(resolve(exe, rpath, lib.name), depth + 1, lib.labels)
    }
  } catch (e) {
    console.log('  '.repeat(depth) + exe, `(failed to parse: ${e.message})`)
  }
}

const deps = new Map
function walkLibs(exe) {
  if (deps.has(exe)) return
  try {
    const {cmds} = macho.parse(readLib(exe))
    const rpath = cmds.find(c => c.type === 'rpath')?.name
    const libs = []
    for (const cmd of cmds) {
      if (cmd.type === 'load_dylib')
        libs.push({name: cmd.name})
      else if (cmd.type === 'load_weak_dylib')
        libs.push({name: cmd.name, labels: ['weak']})
      else if (cmd.type === 'reexport_dylib')
        libs.push({name: getReexportDylibName(cmd), labels: ['reexport']})
    }
    deps.set(exe, libs)
    for (const lib of libs) {
      walkLibs(resolve(exe, rpath, lib.name))
    }
  } catch (e) {
    deps.set(exe, [])
  }
}

printLibs(rootExe)

/*
walkLibs(rootExe)

const ideps = new Map
for (const [k, v] of deps.entries())
  for (const {name: d} of v) {
    if (!ideps.has(d)) ideps.set(d, new Set)
    ideps.get(d).add(k)
  }

function reachableFrom(from, links) {
  const q = []
  const visited = new Set
  visited.add(from)
  q.push(from)
  while (q.length) {
    const e = q.shift()
    for (const n of links(e)) {
      if (!visited.has(n)) {
        visited.add(n)
        q.push(n)
      }
    }
  }
  return visited
}

const nodes = reachableFrom('/System/Library/Frameworks/WebKit.framework/Versions/A/WebKit', x => [...ideps.get(x) ?? []])
//printLibs(rootExe)

console.log('digraph {')
for (const k of deps.keys()) {
  if (nodes.has(k))
    console.log(`"${k}" [label="${path.basename(k)}"]`)
}
for (const [k, v] of deps.entries()) {
  if (nodes.has(k))
  for (const dep of v)
    if (nodes.has(dep.name))
    console.log(`"${k}" -> "${dep.name}" [label=" ${dep.labels?.join(', ') ?? ''}"]`)
}
console.log('}')
*/