Re: gettimeofday.c windows version?

[Bruno Haible <bruno@clisp.org>]

Roger Pack wrote:
> I received some complaints saying in mingw it was"requiring windows 8" for
> a certain library.
> 
> "Entry point not found, GetSystemTimePreciseAsFileTime could not be located
> in the dynamic link library KERNEL32.dll".

Indeed, according to <https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime>
the function GetSystemTimePreciseAsFileTime is not present in Windows 7 and
older.

Looking at the table at
<https://en.wikipedia.org/wiki/Microsoft_Windows#Timeline_of_releases> I see
that Windows 7 is out of "extended support" already for more than 2 years.
That means, users with such machines (connected to the internet) live very
dangerously.

Eli: What are the current support statements of Emacs regarding Windows
XP/Vista/7 ?
And should Gnulib declare that the minimum supported version of Windows
is Windows 8?

> Perhaps the following patch?  Thanks! :)
> 
> diff --git a/lib/gettimeofday.c b/lib/gettimeofday.c
> index 36c7920af..428cc4f30 100644
> --- a/lib/gettimeofday.c
> +++ b/lib/gettimeofday.c
> @@ -35,7 +35,7 @@
>  # undef LoadLibrary
>  # define LoadLibrary LoadLibraryA
> 
> -# if !(_WIN32_WINNT >= _WIN32_WINNT_WIN8)
> +# if (_WIN32_WINNT >= _WIN32_WINNT_WIN8)
> 
>  /* Avoid warnings from gcc -Wcast-function-type.  */
>  #  define GetProcAddress \
> 

Nope, this patch is not right.

> "Entry point not found, GetSystemTimePreciseAsFileTime could not be located
> in the dynamic link library KERNEL32.dll".

It looks like some code links directly to GetSystemTimePreciseAsFileTime, and
your user is running it under Windows 7 or older.

Which object file is it that links to GetSystemTimePreciseAsFileTime?
 - If it's not gettimeofday.c, it's not in Gnulib's responsibility.
 - If it is gettimeofday.c, this file must have been compiled with a
   _WIN32_WINNT value >= _WIN32_WINNT_WIN8. You need to look in your
   build files where this value come from. Maybe it is even the default
   with your compiler version; if that version is new enough, that would
   make sense.

Bruno