Source code for mltk.utils.bin2header

"""Utilities for generating a "C" header file from binary data

See the source code on Github: `mltk/utils/bin2header.py <https://github.com/siliconlabs/mltk/blob/master/mltk/utils/bin2header.py>`_
"""
import argparse
import sys
import os
import io
from typing import Union, List



def bin2header(
    input:Union[str,bytes,List[int],List[float]], # pylint: disable=redefined-builtin
    output_path:Union[bool, str, io.IOBase]=None,
    var_name:str='DATA',
    length_var_name:str='DATA_LENGTH',
    dtype:str='const unsigned char',
    attributes:str=None,
    prepend_lines:List[int]=None,
    fmt_str:str=None,
    prepend_header=True
) -> str:
    """Generate C header file from binary input file

    Arguments:
        input: Either path to binary file or binary contents of previously loaded file, or list of integers or floats
        output_path: Output file path or io stream. Use input with .h appended if True
        var_name: Name of C array
        length_var_name: Name of variable to hold length of C array in bytes
        attributes: Attributes to prepend C array variable
        dtype: The data type of the C array
        prepend_lines: List of C lines of code to prepend before the generated array data
            e.g.: #include <stdint.h>
        fmt_str: The formatting string to use for each entry in the data, e.g.: 0x{:02X}
            If omitted then it is automatically determined based on the given data
    Returns:
        Generated header as a string
    """
    def _get_ascii(c):
        if c >= 32 and c < 127 and chr(c) not in '*#\\':
            return chr(c)
        return '.'

    if attributes is None:
        attributes = ''

    if isinstance(input, str):
        if output_path is True:
            output_path = input + '.h'

        with open(input, 'rb') as f:
            data = f.read()
    else:
        data = input

    out = ''
    if prepend_header:
        out += 'pragma once\n'
        out += '// The following was automatically generated by bin2header.py\n\n'

    if prepend_lines:
        if isinstance(prepend_lines, str):
            prepend_lines = list(prepend_lines)
        for line in prepend_lines:
            if not line.endswith(('\n', '\r')):
                line += '\n'
            out += line
        out += '\n'

    out += f'const unsigned int {length_var_name} = {len(data)};\n'
    out += f'{dtype} {var_name}[{len(data)}] {attributes} =\n{{\n'

    l = [ data[i:i+16] for i in range(0, len(data), 16) ]

    if fmt_str is None:
        if isinstance(data, (bytes,bytearray)):
            fmt_str = '0x{:02X}'
        elif isinstance(data[0], float):
            fmt_str = '{:6.3f}'
        else:
            fmt_str = '{:5d}'

    max_line_len = 0
    for i, x in enumerate(l):
        line = ','.join([fmt_str.format(c) for c in x ])
        if len(line) > max_line_len:
            max_line_len = len(line) + 1
        out += line
        if i < len(l) -1:
            out += ','
        else:
            out += ' ' * (max_line_len - len(line))

        if isinstance(data, (bytes,bytearray)):
            out += f' /* {i*16:6d}: '
            out += ''.join([_get_ascii(c) for c in x])
            out += ' */'

        out += '\n'

    out += '};\n'

    if output_path:
        if isinstance(output_path, str):
            with open(output_path, 'w') as f:
                f.write(out)
        elif isinstance(output_path, io.IOBase):
            output_path.write(out)

    return out



def main():
    parser = argparse.ArgumentParser(description='Generate C header file from binary input file')
    parser.add_argument('input', help='Input file')
    parser.add_argument('-o', '--output', required=False , help='Output file. Use input with .h appended if omitted')
    parser.add_argument('-n', '--name', required=False , help='Name of C array. Use input filename if omitted')
    parser.add_argument('-a', '--attributes', default=None, help='Attributes to prepend C array variable')

    args = parser.parse_args()
    if not args:
        return 1


    if not args.name:
        args.name = os.path.splitext(os.path.basename(args.input))[0].upper().replace('-', '_').replace(' ', '_').replace('.', '_')

    bin2header(
        input=args.input,
        output_path=args.output,
        var_name=args.name,
        attributes=args.attributes,
    )

    return 0


if __name__ == '__main__':
    sys.exit(main())