Add a tool that will tell which git projects are used for a build target

#!/usr/bin/env python3

import argparse

import os

import subprocess

import sys

def get_build_var(var):

  return subprocess.run(["build/soong/soong_ui.bash","--dumpvar-mode", var],

                        check=True, capture_output=True, text=True).stdout.strip()

def get_sources(modules):

  result = subprocess.run(["./prebuilts/build-tools/linux-x86/bin/ninja", "-f",

                           "out/combined-" + os.environ["TARGET_PRODUCT"] + ".ninja",

                           "-t", "inputs", "-d", ] + modules,

                          stderr=subprocess.STDOUT, stdout=subprocess.PIPE, check=False, text=True)

  if result.returncode != 0:

    sys.stderr.write(result.stdout)

    sys.exit(1)

  return set([f for f in result.stdout.split("\n") if not f.startswith("out/")])

def m_nothing():

  result = subprocess.run(["build/soong/soong_ui.bash", "--build-mode", "--all-modules",

                           "--dir=" + os.getcwd(), "nothing"],

                           check=False, stderr=subprocess.STDOUT, stdout=subprocess.PIPE, text=True)

  if result.returncode != 0:

    sys.stderr.write(result.stdout)

    sys.exit(1)

def get_git_dirs():

  text = subprocess.run(["repo","list"], check=True, capture_output=True, text=True).stdout

  return [line.split(" : ")[0] + "/" for line in text.split("\n")]

def get_referenced_projects(git_dirs, files):

  # files must be sorted

  referenced_dirs = set()

  prev_dir = None

  for f in files:

    # Optimization is ~5x speedup for large sets of files

    if prev_dir:

      if f.startswith(prev_dir):

        referenced_dirs.add(d)

        continue

    for d in git_dirs:

      if f.startswith(d):

        referenced_dirs.add(d)

        prev_dir = d

        break

  return [d[0:-1] for d in referenced_dirs]

def main(argv):

  # Argument parsing

  ap = argparse.ArgumentParser(description="List the required git projects for the given modules")

  ap.add_argument("--products", nargs="*",

                  help="The TARGET_PRODUCT to check. If not provided just uses whatever has"

                        + " already been built")

  ap.add_argument("--variants", nargs="*",

                  help="The TARGET_BUILD_VARIANTS to check. If not provided just uses whatever has"

                        + " already been built, or eng if --products is supplied")

  ap.add_argument("--modules", nargs="*",

                  help="The build modules to check, or droid it not supplied")

  ap.add_argument("--why", nargs="*",

                  help="Also print the input files used in these projects, or \"*\" for all")

  args = ap.parse_args(argv[1:])

  modules = args.modules if args.modules else ["droid"]

  # Get the list of sources for all of the requested build combos

  if not args.products and not args.variants:

    sources = get_sources(modules)

  else:

    if not args.products:

      sys.stderr.write("Error: --products must be supplied if --variants is supplied")

      sys.exit(1)

    sources = set()

    build_num = 1

    for product in args.products:

      os.environ["TARGET_PRODUCT"] = product

      variants = args.variants if args.variants else ["user", "userdebug", "eng"]

      for variant in variants:

        sys.stderr.write(f"Analyzing build {build_num} of {len(args.products)*len(variants)}\r")

        os.environ["TARGET_BUILD_VARIANT"] = variant

        m_nothing()

        sources.update(get_sources(modules))

        build_num += 1

    sys.stderr.write("\n\n")

  sources = sorted(sources)

  # Print the list of git directories that has one or more of the sources in it

  for project in sorted(get_referenced_projects(get_git_dirs(), sources)):

    print(project)

    if "*" in args.why or project in args.why:

      prefix = project + "/"

      for f in sources:

        if f.startswith(prefix):

          print("  " + f)

if __name__ == "__main__":

  sys.exit(main(sys.argv))

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