oot/tools/preprocess.py

#!/usr/bin/env python3

# SPDX-FileCopyrightText: © 2024 ZeldaRET
# SPDX-License-Identifier: CC0-1.0

# Usage: preprocess.py [flags] -- [compile command minus input file...] [single input file]
# Preprocess a C file to:
# * Re-encode from UTF-8 to EUC-JP (the repo uses UTF-8 for text encoding, but
#   the strings in the ROM are encoded in EUC-JP)
# * Replace `#pragma increment_block_number` with fake structs for controlling BSS ordering

import argparse
from pathlib import Path
import os
import tempfile
import subprocess
import sys


def fail(message):
    print(message, file=sys.stderr)
    sys.exit(1)


def process_file(version, filename, input, output):
    output.write(f'#line 1 "{filename}"\n')
    for i, line in enumerate(input, start=1):
        if line.startswith("#pragma increment_block_number "):
            # Grab pragma argument and remove quotes
            arg = line.strip()[len("#pragma increment_block_number ") + 1 : -1]
            amount = 0
            for part in arg.split():
                kv = part.split(":")
                if len(kv) != 2:
                    fail(
                        f"{filename}:{i}: increment_block_number must be followed by a list of version:amount pairs"
                    )
                if kv[0] != version:
                    continue
                try:
                    amount = int(kv[1])
                except ValueError:
                    fail(
                        f"{filename}:{i}: increment_block_number amount must be an integer"
                    )

            # Always generate at least one struct so that fix_bss.py can know where the increment_block_number pragmas are
            if amount == 0:
                amount = 256

            # Write fake structs for BSS ordering
            for j in range(amount):
                output.write(f"struct increment_block_number_{i:05}_{j:03};\n")
            output.write(f'#line {i + 1} "{filename}"\n')
        else:
            output.write(line)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("-v", "--oot-version", help="Which version should be processed")
    parser.add_argument(
        "args",
        nargs="+",
    )

    args = parser.parse_args()

    filename = Path(args.args[-1])
    with tempfile.TemporaryDirectory(prefix="oot_") as tmpdir:
        tmpfile = Path(tmpdir) / filename.name

        with open(filename, mode="r", encoding="utf-8") as input:
            with open(tmpfile, mode="w", encoding="euc-jp") as output:
                process_file(args.oot_version, filename, input, output)

        compile_command = args.args[:-1] + ["-I", filename.parent, tmpfile]
        process = subprocess.run(compile_command)
        return process.returncode


if __name__ == "__main__":
    try:
        sys.exit(main())
    except KeyboardInterrupt:
        sys.exit(1)