third_party/yasm/run_yasm.py

   1 # Copyright 2014 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """A wrapper to run yasm.
   6
   7 Its main job is to provide a Python wrapper for GN integration, and to write
   8 the makefile-style output yasm generates in stdout to a .d file for dependency
   9 management of .inc files.
  10
  11 Run with:
  12   python run_yasm.py <yasm_binary_path> <all other yasm args>
  13
  14 Note that <all other yasm args> must include an explicit output file (-o). This
  15 script will append a ".d" to this and write the dependencies there. This script
  16 will add "-M" to cause yasm to write the deps to stdout, so you don't need to
  17 specify that.
  18 """
  19
  20 import argparse
  21 import sys
  22 import subprocess
  23
  24 # Extract the output file name from the yasm command line so we can generate a
  25 # .d file with the same base name.
  26 parser = argparse.ArgumentParser()
  27 parser.add_argument("-o", dest="objfile")
  28 options, _ = parser.parse_known_args()
  29
  30 objfile = options.objfile
  31 depfile = objfile + '.d'
  32
  33 # Assemble.
  34 result_code = subprocess.call(sys.argv[1:])
  35 if result_code != 0:
  36   sys.exit(result_code)
  37
  38 # Now generate the .d file listing the dependencies. The -M option makes yasm
  39 # write the Makefile-style dependencies to stdout, but it seems that inhibits
  40 # generating any compiled output so we need to do this in a separate pass.
  41 # However, outputting deps seems faster than actually assembling, and yasm is
  42 # so fast anyway this is not a big deal.
  43 #
  44 # This guarantees proper dependency management for assembly files. Otherwise,
  45 # we would have to require people to manually specify the .inc files they
  46 # depend on in the build file, which will surely be wrong or out-of-date in
  47 # some cases.
  48 deps = subprocess.check_output(sys.argv[1:] + ['-M'])
  49 with open(depfile, "wb") as f:
  50   f.write(deps)
  51