Re: [PATCH 0/2] MR4720: Implement test_continue() for amd64

[Jinoh Kang (＠iamahuman)]

Hello there! Thanks for your contribution.

Apropos commit "ntdll/tests: Move test_continue() to be used for all platforms":

I think there is a better way to test `NtContinue()` across platforms. You're approach of sharing the `test_continue()` function header/footer works, but ends up branching on the architecture *twice*.

```c
static void test_continue(void)
{
    ...

#ifdef __x86_64__
    static const BYTE call_func[] =
    {
        ...
    };
#elif defined(__aarch64__)
    static const DWORD call_func[] =
    {
        ...
    };
#else
    ...
#endif

    ...
    memcpy( func_ptr, call_func, sizeof(call_func) );
    FlushInstructionCache( GetCurrentProcess(), func_ptr, sizeof(call_func) );

    func_ptr( &contexts, FALSE, NtContinue, pRtlCaptureContext );

#ifdef __x86_64__
    ...
#elif defined(__aarch64__)
    ...
#endif
    ...
}
```

Notice that there is little code shared between architectures, other than `NtContinue` and `RtlCaptureContext`.

Instead, I suggest that you define the entire `test_continue()` per each architecture:

```c
#ifdef __x86_64__ 
...
static void test_thread_context(void)
{
    ...
#undef COMPARE
}

static void test_continue(void)
{
    ...

    static const BYTE call_func[] =
    {
        ...
    };

    ...
    memcpy( func_ptr, call_func, sizeof(call_func) );
    FlushInstructionCache( GetCurrentProcess(), func_ptr, sizeof(call_func) );

    func_ptr( &contexts, FALSE, NtContinue, pRtlCaptureContext );

    ...
}

static void test_wow64_context(void)
{
    ...
}
...
#elif defined(__arch64__)
...
static void test_continue(void)
{
    ...
}
```

Even if this leads to code duplication, this allows us flexibility to extend `test_continue` with arch-specific logic in the future, and avoids interleaving of different test code for each architecture.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4720#note_56305