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Date: Wed, 19 May 2021 11:02:08 -0700 (PDT)
From: Jeremy Drake <cygwin@jdrake.com>
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To: cygwin-patches@cygwin.com
Subject: Re: [RFC] FAST_CWD warnings on ARM64 insider preview
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On Wed, 19 May 2021, Corinna Vinschen wrote:

> > +#ifndef IMAGE_FILE_MACHINE_ARM64
> > +#define IMAGE_FILE_MACHINE_ARM64 0xAA64
> > +#endif
>
> IMAGE_FILE_MACHINE_ARM64 is already defined for some time in winnt.h
> so we won't need the ifdef.

OK.  Was just matching what was done with PROCESSOR_ARCHITECTURE_ARM64.

> > +      typedef BOOL (WINAPI * IsWow64Process2_t)(HANDLE hProcess, USHORT *pProcessMachine, USHORT *pNativeMachine);
> > +      IsWow64Process2_t pfnIsWow64Process2 = (IsWow64Process2_t)GetProcAddress(GetModuleHandle("kernel32.dll"), "IsWow64Process2");
> > +      if (pfnIsWow64Process2 && pfnIsWow64Process2(GetCurrentProcess(), &procmachine, &nativemachine) && nativemachine == IMAGE_FILE_MACHINE_ARM64)
>
> We're having the autoload mechanism for that, i. e., your patch can get
> rid of the GetModuleHandle/GetProcAddress preliminaries entirely.
>
> By using the LoadDLLfuncEx() expression, failure to load the function
> will result in a return value of FALSE with GetLastError ==
> ERROR_PROC_NOT_FOUND, so this is safe on older systems.

Nice.

> It's easier to understand with a full example, so I took the liberty to
> rewrite your patch accordingly.  Since the idea and the basic work is
> yours, I'd push this under your name, see below.

Looks good.  Thanks