clean-libsodium-di.d

// Cleans up the sodium.di file by removing any extra declarations
// we don't care about, as well as patching a few things up.
module clean;

import std : writeln, lineSplitter, readText, Appender, canFind, endsWith, array, substitute;
import std.file : write;

const LIBSODIUM_LICENSE = `
/*
 * ISC License
 *
 * Copyright (c) 2013-2023
 * Frank Denis <j at pureftpd dot org>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
`;

void main()
{
    const input = readText("sodium.di");
    const lines = input.lineSplitter.array;
    Appender!(char[]) output;
    output.reserve(input.length);

    output.put("// This file was automatically generated by devops/scripts/gen-libsodium-di.bash\n");
    output.put("// The preserved libsodium ISC license is presented below, and extends to this file.\n");
    output.put(LIBSODIUM_LICENSE);
    output.put("module juptune.crypto.libsodium;\n");
    output.put("extern(C) @nogc nothrow:\n");

    for(size_t i = 0; i < lines.length; i++)
    {
        const line = lines[i];

        if(
            line.canFind("extern __gshared")
            || line.canFind("static __gshared")
        ) // A non-libsodium declaration
        {
            continue;
        }
        else if(
            line.canFind("__gshared")
            && (line.canFind(" crypto_") || line.canFind(" sodium_") || line.canFind(" randombytes_"))
        ) // A libsodium function declaration
        {
            output.put(line);
            output.put("\n");
        }
        else if(
            line.canFind("struct")
            && (line.canFind(" crypto_") || line.canFind(" sodium_") || line.canFind(" randombytes_"))
        ) // A libsodium struct
        {
            if(line.endsWith(";"))
                continue;

            output.put(line);       output.put("\n");
            output.put(lines[++i]); output.put("\n"); // {
            while(!lines[i].endsWith("}"))
            {
                // Lines like `const struct my_struct s = void` -> `my_struct s`
                output.put(lines[++i].substitute(
                    "const struct", "",
                    "struct", "",
                ));
                output.put("\n");
            }

            output.put("\n");
        }
    }

    write("libsodium.di", output.data);
}