[Tcl-bugs] [ tcl-Bugs-3508771 ] load tclreg.dll in cygwin tclsh

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Bugs item #3508771, was opened at 2012-03-19 08:35
Message generated for change (Settings changed) made by nijtmans
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Category: 52. Portability Support
Group: current: 8.5.11
Status: Open
>Resolution: Fixed
Priority: 5
Private: No
Submitted By: Jan Nijtmans (nijtmans)
Assigned to: Jan Nijtmans (nijtmans)
Summary: load tclreg.dll in cygwin tclsh

Initial Comment:
Using the stubs mechanism, it should be possible to load tclreg.dll
(compiled with mingw or vc++) in a tclsh compiled with cygwin.
I tried it, and it almost works, but not quite.....

tclreg.dll calls the function TclWinGetPlatformId(), inits init
function:
    if (TclWinGetPlatformId() == VER_PLATFORM_WIN32_NT) {
	regWinProcs = &unicodeProcs;
    } else {
	regWinProcs = &asciiProcs;
    }
 which resides in slot 9 of tclIntPlatStubs. But
cygwin uses the UNIX stubs, which has TclpCreateTempFile()
in slot 9. So, everything seems to work, but in fact a
temporary file is created, and a handle to it
is returned. This handle is != VER_PLATFORM_WIN32_NT,
so this instructs tclreg.dll to use the ASCII variants
of the registry functions.

Solution: move TclpCreateTempFile from slot 9
to slot 22, and put TclWinGetPlatformId in
slot 9. On UNIX, TclWinGetPlatformId  does not
exist, so use some #define to map it back
to TclpCreateTempFile on non-cygwin.

The same potential problem exists with
the functions Tcl_WinUtfToTChar and
Tcl_WinTCharToUtf, which are in the
public API. TclWinGetPlatformId is not
public, but because it is used in tclreg.dll I
would like to make an exception for that.

----------------------------------------------------------------------

Comment By: Jan Nijtmans (nijtmans)
Date: 2012-03-20 03:54

Message:
Implementation for TclWinGetPlatformId,
Tcl_WinUtfToTChar and Tcl_WinTCharToUtf
done and committed to core-8-4-branch,
core-8-5-branch and trunk.

(Since cygwin now switched to tcl 8.5, it
would not have been necessary to do it
for Tcl 8.4, but it worked, so why not....)

Added a dummy TclWinCPUID too, because
this function is in slot 29, the last win32
slot. win32 has more slots than unix, and
this way all unused slots will be set to
NULL in stead of some random value.
And... TclWinCPUID is intel-specific, not
Windows-specific: it can be implemented
on UNIX and cygwin as well, the only
requirement is that it has an Intel (or AMD)
processor. The default implementation
simply returns TCL_ERROR.

The functions Tcl_WinUtfToTChar and
Tcl_WinTCharToUtf had the problem
that MAC_OSX has all UNIX functions
as well, plus its own. Adding UNIX
stub entries would mean that the
two functions Tcl_MacOSXOpenBundleResources
and Tcl_MacOSXOpenVersionedBundleResources
would shift up!!  So I used the trick to put
the two new functions in the place of the
max functions. Tricky, but it works.

So the Tcl_MacOSXOpenBundleResources
stub entry has its own function on OSX, it
contains the function Tcl_WinUtfToTChar
on cygwin, and it has NULL for other
UNIXes. This makes the function
Tcl_WinUtfToTChar effectively hidden
from Cygwin, but - hey - that's exactly
what we want because it should only
be callable by win32 extensions.

Keeping open, because tclInt.decls
contains more functions that could
be called by win32 extensions.

----------------------------------------------------------------------

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