解析mach-o目标文件的胖头

Question

我正在尝试重新编码nm，并且正在努力解析胖头。似乎胖结构的偏移有一些问题。我可能无法很好地进入内存，但无法弄清楚。我想知道我是如何使用指针的，还是我不太了解胖头的工作原理。 当我尝试使用胖文件执行程序时，我获得了ppc架构的良好输出，但是如果i386架构失败，我的函数将检查在特定偏移量处是否存在有效的mach_header。 这是一些代码。 谢谢您的帮助。

void                        process_fat_header_32(t_map *file,
                            t_arch *arch, t_header *header)
{
    struct fat_arch     *fat_arch;
    struct fat_header   *fat_header;
    uint32_t            val;
    uint32_t            i;
    const char          *cpu;
    char                *tmp;

    i = 0;
    fat_header = header->fat_header;
    val = should_swap_32(arch, fat_header->nfat_arch);
    fat_arch = (struct fat_arch *)(fat_header + 1);
    while (i < val)
    {
        fat_arch = (void *)file->ptr + sizeof(struct fat_header) +
        (i * sizeof(struct fat_arch));
        cpu = cpu_type_name(should_swap_32(arch, fat_arch->cputype));
        if (!ft_strcmp(cpu, "unknown"))
            return ;
        print_architecture(cpu, file->file[g_idx]);
        printf("offset = %d\n", should_swap_32(arch, fat_arch->offset));
        tmp = file->ptr;
        file->ptr = file->ptr + should_swap_32(arch, fat_arch->offset);
        launch_process(file, arch, header);
        file->ptr = tmp;
        i++;
    }
}