generate_files.py

# ---HOW TO---
# Create one function per file you want to generate. The file will have the same name as the function.
# Each function should compute and return the content of the corresponding file as a string.
# Then call `generate`:
# ```python
# def some_function_that_will_generate_a_file():
#     return "The content of the file"
#
# def another_function():
#     return "Another file"
#
# generate(
#     folder="generated", # The name of the output folder where the files will be generated. /!\ Don't put anything manually in that folder, it is erased and regenerated each time you call `generate()`.
#     files=[
#         some_function_that_will_generate_a_file,
#         another_function,
#     ]
# )
# ```
# ------------


def SUFFIX():
    return "___TEMP"


def clear_generated_folder(files, directory):
    import os

    for file in os.listdir(directory):
        path = os.path.join(directory, file)
        if os.path.isfile(path):
            if not file[:-4] in map(lambda file: file.__name__, files):
                os.remove(path)


def output_folder(path_relative_to_project_root):
    import os
    import sys
    from pathlib import Path

    root_folder = Path(sys.argv[0]).parent
    return os.path.join(root_folder, path_relative_to_project_root)


def generate_one(function, folder, calling_file):
    generate_file(
        f"{function.__name__}{SUFFIX()}",
        f"{function.__name__}",
        function(),
        folder,
        calling_file,
    )


def file_path(name, folder):
    import os

    return os.path.join(folder, name) + ".inl"


def create_folder_ifn(path):
    import os

    try:
        os.makedirs(path)
    except FileExistsError:
        pass


def create_file_ifn(path):
    try:
        with open(path, "x"):
            pass
    except FileExistsError:
        pass


def generate_file(name, name_without_suffix, content, folder, calling_file):
    path = file_path(name, folder)
    create_file_ifn(path)
    with open(path, "w") as f:
        f.write(heading(name_without_suffix, calling_file) + content)


def heading(function_name, calling_file):
    import os
    import sys

    path_to_generator = os.path.basename(calling_file if calling_file else sys.argv[0])
    return f"""/* -----------------------------------------------------------------------------
 * This file was automatically generated by a Python script.
 * PLEASE DON'T EDIT IT DIRECTLY, your changes would be overwritten the next time the script is run.
 * Instead, go to "{path_to_generator}" and edit the "{function_name}" function there.
 * -----------------------------------------------------------------------------
 */
"""


def apply_clang_format_on_generated_files(folder):
    from os import path
    from pathlib import Path
    from importlib.machinery import SourceFileLoader

    apply_clang_format = SourceFileLoader(
        "apply_clang_format",
        path.join(Path(path.abspath(__file__)).parent, "apply_clang_format.py"),
    ).load_module()
    apply_clang_format.apply_clang_format(
        folder=folder,
        print_result=False,
    )


def files_are_equal(file1_path, file2_path):
    with open(file1_path, "rb") as file1, open(file2_path, "rb") as file2:
        while True:
            byte1 = file1.read(1)
            byte2 = file2.read(1)

            if byte1 != byte2:
                return False

            if not byte1:  # Reached end of file
                return True


# Remove the newly created file if it the same as the old one (avoids to overwrite the old one which would force cmake to recompile it).
# Otherwise, replace the old one with the new one.
def cleanup(function, folder):
    import os

    path = file_path(f"{function.__name__}", folder)
    path_temp = file_path(f"{function.__name__}{SUFFIX()}", folder)

    if not os.path.exists(path):
        os.rename(path_temp, path)
        return

    if files_are_equal(path, path_temp):
        os.remove(path_temp)
    else:
        os.remove(path)
        os.rename(path_temp, path)


def generate(
    folder="generated", files=[], should_apply_clang_format=True, calling_file=""
):
    folder = output_folder(folder)
    create_folder_ifn(folder)

    for function in files:
        generate_one(function, folder, calling_file)

    if should_apply_clang_format:
        apply_clang_format_on_generated_files(folder)

    for function in files:
        cleanup(function, folder)

    clear_generated_folder(files, folder)