/*
 * Minimal bootstrap RTL (runtime library) - String functions.
 *
 * Copyright © 2025 Samuel Lidén Borell <samuel@kodafritt.se>
 *
 * SPDX-License-Identifier: EUPL-1.2+ OR LGPL-2.1-or-later
 */
#include <assert.h>
#include "rtl.h"
#include "internal.h"


const unsigned char *SLUL__decode_string(
        const struct String *str,
        SlulInt *len_out)
{
    const unsigned char *s = (const unsigned char *)str;
    unsigned char format = (unsigned char)*s;
    SlulInt len;
    if (format < SLUL_SL_UPTO_17F) {
        len = format;
        s++;
    } else if (format < SLUL_SL_UPTO_1017F) {
        len = 0x80 + s[1];
        s += 2;
    } else if (format < SLUL_SL_UPTO_10001017F) {
        len = 0x180U + (s[1] |
                        s[2]<<8);
        s += 3;
    } else {
        len = 0x10180U + (s[1] |
                          s[2]<<8 |
                          s[3]<<16);
        s += 4;
    }
    if (len_out) *len_out = len;
    return s;
}