impeller/tools/xxd.py

# Copyright 2013 The Flutter Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import sys

import argparse
import errno
import os
import struct

def MakeDirectories(path):
    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise

# Dump the bytes of file into a C translation unit.
# This can be used to embed the file contents into a binary.
def Main():
  parser = argparse.ArgumentParser()
  parser.add_argument("--symbol-name",
                    type=str, required=True,
                    help="The name of the symbol referencing the data.")
  parser.add_argument("--output-header",
                    type=str, required=True,
                    help="The header file containing the symbol reference.")
  parser.add_argument("--output-source",
                    type=str, required=True,
                    help="The source file containing the file bytes.")
  parser.add_argument("--source",
                    type=str, required=True,
                    help="The source file whose contents to embed in the output source file.")

  args = parser.parse_args()

  assert(os.path.exists(args.source))

  output_header = os.path.abspath(args.output_header)
  output_source = os.path.abspath(args.output_source)

  MakeDirectories(os.path.dirname(output_header))
  MakeDirectories(os.path.dirname(output_source))

  with open(args.source, "rb") as source, open(output_source, "w") as output:
    data_len = 0
    output.write(f"const unsigned char impeller_{args.symbol_name}_data[] =\n")
    output.write("{\n")
    while True:
      byte = source.read(1)
      if not byte:
        break
      data_len += 1
      output.write(f"{ord(byte)},")
    output.write("};\n")
    output.write(f"const unsigned long impeller_{args.symbol_name}_length = {data_len};\n")

  with open(output_header, "w") as output:
    output.write("#pragma once\n")
    output.write("#ifdef __cplusplus\n")
    output.write("extern \"C\" {\n")
    output.write("#endif\n\n")

    output.write(f"extern unsigned char impeller_{args.symbol_name}_data[];\n")
    output.write(f"extern unsigned long impeller_{args.symbol_name}_length;\n\n")

    output.write("#ifdef __cplusplus\n")
    output.write("}\n")
    output.write("#endif\n")

if __name__ == '__main__':
  Main()