[Vm-dev] Raise minimum supported Windows API from XP to Vista (was: Identify console executable and standard one)

Eliot Miranda eliot.miranda at gmail.com
Mon Apr 23 20:33:25 UTC 2018


Hi Alistair,

On Mon, Apr 23, 2018 at 1:06 PM, Alistair Grant <akgrant0710 at gmail.com>
wrote:

>
> Hi Eliot & Vincent,
>
> On Mon, Apr 23, 2018 at 10:00:12AM -0700, Eliot Miranda wrote:
> >
> > Hi Alistair,
> >
> >
> > > On Apr 23, 2018, at 2:46 AM, Alistair Grant <akgrant0710 at gmail.com>
> wrote:
> > >
> > >
> > > Hi Everyone,
> > >
> > >
> > > I have some test code that correctly identifies whether stdin on
> Windows
> > > is a console or redirected, in both windows command terminals (cmd.exe)
> > > and cygwin mintty (the current code only works for cmd.exe, not for
> > > cygwin terminals).
> > >
> > > However it relies on the Windows Vista API, i.e. _WIN32_WINNT >=
> > > 0x0600, and at the moment we set the minimum supported version to
> > > Windows XP (0x0501).
> > >
> > > Since Windows XP is no longer supported, I can't see any problem with
> > > raising the minimum version to Windows Vista (which also isn't
> > > supported, but should give us maximum compatibility), but wanted to
> > > check first.
> > >
> > > Are there any objections to raising the minimum API level to Windows
> > > Vista?
> >
> > Not from me.  But it would be nice if the resulting executable still
> > ran in Windows NT.  Is that still possible?  What does the code look
> > like?
>
> If we make this change I think the chances of it working on NT are next
> to zero.
>
> Actually, I'd be surprised if the current VM ran on NT since it is
> explicitly asking for the XP API, but I haven't tested it.
>
> The code is available at:
>
> https://fossies.org/linux/misc/vim-8.0.tar.bz2/vim80/src/iscygpty.c
> https://fossies.org/linux/misc/vim-8.0.tar.bz2/vim80/src/iscygpty.h


So if you look at lines 60 through 101 you'll see the standard technique
for getting around the version issue:

   60 //#define USE_DYNFILEID
   61 #ifdef USE_DYNFILEID
   62 typedef BOOL (WINAPI *pfnGetFileInformationByHandleEx)(
   63         HANDLE                    hFile,
   64         FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
   65         LPVOID                    lpFileInformation,
   66         DWORD                     dwBufferSize
   67 );
   68 static pfnGetFileInformationByHandleEx pGetFileInformationByHandleEx
= NULL;
   69
   70 # ifndef USE_FILEEXTD
   71 static BOOL WINAPI stub_GetFileInformationByHandleEx(
   72         HANDLE                    hFile,
   73         FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
   74         LPVOID                    lpFileInformation,
   75         DWORD                     dwBufferSize
   76         )
   77 {
   78     return FALSE;
   79 }
   80 # endif
   81
   82 static void setup_fileid_api(void)
   83 {
   84     if (pGetFileInformationByHandleEx != NULL) {
   85         return;
   86     }
   87     pGetFileInformationByHandleEx = (pfnGetFileInformationByHandleEx)
   88         GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")),
   89                 "GetFileInformationByHandleEx");
   90     if (pGetFileInformationByHandleEx == NULL) {
   91 # ifdef USE_FILEEXTD
   92         pGetFileInformationByHandleEx = GetFileInformationByHandleEx;
   93 # else
   94         pGetFileInformationByHandleEx =
stub_GetFileInformationByHandleEx;
   95 # endif
   96     }
   97 }
   98 #else
   99 # define pGetFileInformationByHandleEx  GetFileInformationByHandleEx
  100 # define setup_fileid_api()
  101 #endif


If USE_DYNFILEID is defined then the code searches kernel32.dll and uses
the function if found.  So the safe way to write this is to follow the
approach given by USE_DYNFILEID (no need to implement setup_fileid_api; all
thats needed is the statements therefore prepended to the use of
pGetFileInformationByHandleEx).  If GetFileInformationByHandleEx exists in
kernel32.dll use it, otherwise fall back on our existing code.  That way we
should be able to keep the Windows XP build level.  People still use it a
lot (especially students in poor countries) and I'd rather wait until we
can jump forward beyond Vista to make the change ;-) ;-) ;-)


Does that make sense?  You'll see some of this code in the win32 subsystem
already; grep GetProcAddress  platforms/win32/vm/*
platforms/win32/plugins/*/*


> On Mon, Apr 23, 2018 at 05:37:45PM +0000, Vincent.Blondeau at lamresearch.com
> wrote:
> >
> > Hi Alistair,
> >
> > I made some code that have the same goal, but I am also stuck to
> > identify the Cygwin and minty terminals, I tried the approach with the
> > name of the pipes, but the pipes have always the same name. You can
> > take a look at my code there:
> > https://github.com/OpenSmalltalk/opensmalltalk-vm/compare/Cog...
> VincentBlondeau:addStdoutIsConsolePrimitive
>
> The vim code does something very similar, but haven't looked closely.
>
>
> > Have you been thinking to another solution?
>
> No :-)
>
>
> > Which function do you need that is not existing under XP?
>
> The use of FILE_NAME_INFO and GetFileInformationByHandleEx() requires
> Vista (see iscygpty.c above).
>
>
> Cheers,
> Alistair
>
>
>
> > Thanks,
> >
> > Cheers,
> > Vincent
> >
> > -----Original Message-----
> > From: Vm-dev [mailto:vm-dev-bounces at lists.squeakfoundation.org] On
> Behalf Of Alistair Grant
> > Sent: Monday, April 23, 2018 2:47
> > To: Open Smalltalk Virtual Machine Development Discussion <vm-dev at lists.
> squeakfoundation.org>
> > Subject: [Vm-dev] Raise minimum supported Windows API from XP to Vista
> (was: Identify console executable and standard one)
> >
> >
> > Hi Everyone,
> >
> >
> > I have some test code that correctly identifies whether stdin on Windows
> is a console or redirected, in both windows command terminals (cmd.exe) and
> cygwin mintty (the current code only works for cmd.exe, not for cygwin
> terminals).
> >
> > However it relies on the Windows Vista API, i.e. _WIN32_WINNT >= 0x0600,
> and at the moment we set the minimum supported version to Windows XP
> (0x0501).
> >
> > Since Windows XP is no longer supported, I can't see any problem with
> raising the minimum version to Windows Vista (which also isn't supported,
> but should give us maximum compatibility), but wanted to check first.
> >
> > Are there any objections to raising the minimum API level to Windows
> Vista?
> >
> >
> >
> > Thanks,
> > Alistair
>
>

-- 
_,,,^..^,,,_
best, Eliot
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