#!/usr/bin/env python
#
# Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
# for details. All rights reserved. Use of this source code is governed by a
# BSD-style license that can be found in the LICENSE file.

# Generates an assembly source file the defines a symbol with the bytes from
# a given file.

import os
import sys
from optparse import OptionParser

def Main():
  parser = OptionParser()
  parser.add_option("--output",
                    action="store", type="string",
                    help="output assembly file name")
  parser.add_option("--input",
                    action="store", type="string",
                    help="input binary blob file")
  parser.add_option("--symbol_name",
                    action="store", type="string")
  parser.add_option("--executable",
                    action="store_true", default=False)
  parser.add_option("--target_os",
                    action="store", type="string")

  (options, args) = parser.parse_args()
  if not options.output:
    sys.stderr.write("--output not specified\n")
    parser.print_help();
    return -1
  if not options.input:
    sys.stderr.write("--input not specified\n")
    parser.print_help();
    return -1
  if not os.path.isfile(options.input):
    sys.stderr.write("input file does not exist: %s\n" % options.input)
    parser.print_help();
    return -1
  if not options.symbol_name:
    sys.stderr.write("--symbol_name not specified\n")
    parser.print_help();
    return -1
  if not options.target_os:
    sys.stderr.write("--target_os not specified\n")
    parser.print_help();
    return -1

  with open(options.output, "w") as output_file:
    if options.target_os in ["mac", "ios"]:
      if options.executable:
        output_file.write(".text\n")
      else:
        output_file.write(".const\n")
      output_file.write(".global _%s\n" % options.symbol_name)
      output_file.write(".balign 32\n")
      output_file.write("_%s:\n" % options.symbol_name)
    elif options.target_os in ["win"]:
      output_file.write("ifndef _ML64_X64\n")
      output_file.write(".model flat, C\n")
      output_file.write("endif\n")
      if options.executable:
        output_file.write(".code\n")
      else:
        output_file.write(".const\n")
      output_file.write("public %s\n" % options.symbol_name)
      output_file.write("%s label byte\n" % options.symbol_name)
    else:
      if options.executable:
        output_file.write(".text\n")
        output_file.write(".type %s STT_FUNC\n" % options.symbol_name)
      else:
        output_file.write(".section .rodata\n")
        output_file.write(".type %s STT_OBJECT\n" % options.symbol_name)
      output_file.write(".global %s\n" % options.symbol_name)
      output_file.write(".balign 32\n")
      output_file.write("%s:\n" % options.symbol_name)

    with open(options.input, "rb") as input_file:
      if options.target_os in ["win"]:
        for byte in input_file.read():
          output_file.write("byte %d\n" % ord(byte))
        output_file.write("end\n")
      else:
        for byte in input_file.read():
          output_file.write(".byte %d\n" % ord(byte))

    if options.target_os not in ["mac", "ios", "win"]:
      output_file.write(".size {0}, .-{0}\n".format(options.symbol_name))

  return 0

if __name__ == "__main__":
  sys.exit(Main())