static void
command_regs(struct mi_process proc)
{
    struct mi_registers regs = get_process_registers(proc);
    printf("rax = %#018lx rcx = %#018lx\n"
           "rbp = %#018lx rbx = %#018lx\n"
           "rdx = %#018lx rsi = %#018lx\n"
           "rdi = %#018lx rip = %#018lx\n"
           "rsp = %#018lx\n", 
           regs.rax, regs.rcx, regs.rbp, regs.rbx, 
           regs.rdx, regs.rsi, regs.rdi, regs.rip, 
           regs.rsp);
}

static void
command_step(struct mi_process proc)
{
    int comp_unit;
    
    struct mi_registers regs = get_process_registers(proc);
    struct mi_sourcepoint *sp = pc_to_sourcepoint(proc, regs.rip - proc.base_address, &comp_unit);
    struct mi_sourcepoint *next_sp;
    
    do {
        ptrace(PTRACE_SINGLESTEP, proc.pid, 0, 0);
        waitpid(proc.pid, 0, 0);
        regs = get_process_registers(proc);
        long instruction = ptrace(PTRACE_PEEKDATA, proc.pid, regs.rip, NULL);
        next_sp = pc_to_sourcepoint(proc, regs.rip - proc.base_address, &comp_unit);
        if (!next_sp) break;
    } while (next_sp->line == sp->line);
    
    print_sourcepoint(proc, comp_unit, next_sp);
}

static void
command_start(struct mi_process proc)
{
    u64 main_address = proc.base_address + proc.main_address;
    long saved_instruction = place_breakpoint_at(proc, main_address);
    run_until_breakpoint_and_restore(proc, main_address, saved_instruction);
}

static void
command_next(struct mi_process proc)
{
    int comp_unit;
    
    struct mi_registers regs = get_process_registers(proc);
    struct mi_sourcepoint *sp = pc_to_sourcepoint(proc, regs.rip - proc.base_address, &comp_unit);
    struct mi_sourcepoint *next_sp;
    
    do {
        ptrace(PTRACE_SINGLESTEP, proc.pid, 0, 0);
        waitpid(proc.pid, 0, 0);
        regs = get_process_registers(proc);
        
        long instruction = ptrace(PTRACE_PEEKDATA, proc.pid, regs.rip, NULL);
        if (is_call_instruction(instruction)) {
            u64 call_at = regs.rip;
            
            // Do single step, get return address from stack, place breakpoint there, continue
            ptrace(PTRACE_SINGLESTEP, proc.pid, 0, 0);
            waitpid(proc.pid, 0, 0);
            regs = get_process_registers(proc);
            
            long return_address = ptrace(PTRACE_PEEKDATA, proc.pid, regs.rsp, NULL);
            long saved_instruction = place_breakpoint_at(proc, return_address);
            run_until_breakpoint_and_restore(proc, return_address, saved_instruction);
            // TODO: disambiguate recursive calls
            
            regs = get_process_registers(proc);
        }
        // TODO: repXXX
        
        //printf("%#lx\n", regs.rip - proc.base_address);
        next_sp = pc_to_sourcepoint(proc, regs.rip - proc.base_address, &comp_unit);
        
        if (!next_sp) break;
    } while (next_sp->line == sp->line);
    
    print_sourcepoint(proc, comp_unit, next_sp);
}

static void
command_list(struct mi_process proc)
{
    int comp_unit;
    struct mi_registers regs = get_process_registers(proc);
    struct mi_sourcepoint *sp = pc_to_sourcepoint(proc, regs.rip - proc.base_address, &comp_unit);
    print_sourcepoint(proc, comp_unit, sp);
}

static void
command_cont(struct mi_process proc)
{
    ptrace(PTRACE_CONT, proc.pid, 0, 0);
}

static void
command_stop(struct mi_process proc)
{
    kill(proc.pid, SIGINT);
    // TODO
}