[MACTCL] Segmentation fault because of TK Framework conflict X11 library

[Perrog <pe...@gm...>]

Hi!

I'm trying to build an TCL/Tk extension. I manage to build it
completely, albeit some linker warnings about multiple definition,
but when I run a sample script I get a segmentation fault when the C
source calls X-windows routines. This is a sample GDB session:

/src/gnu-src/nxtvepg-2.7.7> gdb build-powerpc/nxtvepg
GNU gdb 6.3.50-20050815 (Apple version gdb-573) (Fri Oct 20 15:54:33 GMT 2006)
<copyleft cutted>
This GDB was configured as "powerpc-apple-darwin"...Reading symbols
for shared libraries ...... done

(gdb) run
Starting program: /src/gnu-src/nxtvepg-2.7.7/build-powerpc/nxtvepg
Reading symbols for shared libraries
...................................................................+....+
done
Reading symbols for shared libraries . done

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x732e2078
0x0004d718 in wm_detect (dpy=0x68a008) at epgui/wmhooks.c:254
254         Window root = DefaultRootWindow(dpy);
(gdb) bt
#0  0x0004d718 in wm_detect (dpy=0x68a008) at epgui/wmhooks.c:254
#1  0x0004daf0 in WmHooks_Init (interp=0x2fd608) at epgui/wmhooks.c:488
#2  0x000434a4 in main (argc=1, argv=0x16f74c) at epgui/epgmain.c:3015
(gdb) list
249     #define INIT_ATOM(dpy,atom) atom = XInternAtom(dpy,#atom,False)
250
251     static void
252     wm_detect(Display *dpy)
253     {
254         Window root = DefaultRootWindow(dpy);
255
256         INIT_ATOM(dpy, _NET_SUPPORTED);
257         INIT_ATOM(dpy, _NET_WM_STATE);
258         INIT_ATOM(dpy, _NET_WM_STATE_STAYS_ON_TOP);
(gdb)

I'm trying to deduce the error and think this has to do with the
linker warnings. Partly because I experience a similar event (not
related to Tcl!), partly because I don't know otherwise. In more
detail, the linker warns about multiple definitions of X11-functions.
And I think Tk.framework is linked against the static X11-libray, but
my extension links against a shared X11-library (perhaps newer.) And I
can't just strip away -lX11 and -lXmu because then linking fails with
undefined symbols XFree, XGetErrorText, XGetWindowAttributes,
XmuClientWindow.

What shall I do to make it work? May I need to rebuilt the
"TclTkAquaBI" or Tk.framework and link against shared X11 library? Is
there already a such pre-built binary?

Back to the linker warning. It looks like

$ cc  -o build-powerpc/nxtvepg $(OBJS) -L/usr/local/lib
-L/usr/X11R6/lib -framework tk -framework tcl -lm -lX11 -lXmu
-lpthread
/usr/bin/ld: warning multiple definitions of symbol _XGetGeometry
/Library/Frameworks/tk.framework/tk(single module) definition of _XGetGeometry
/usr/X11R6/lib/libX11.dylib(GetGeom.o) definition of _XGetGeometry
...
/usr/bin/ld: warning multiple definitions of symbol _XSetErrorHandler
/Library/Frameworks/tk.framework/tk(single module) definition of
_XSetErrorHandler
/usr/X11R6/lib/libX11.dylib(ErrHndlr.o) definition of _XSetErrorHandler

And I can check what shared libraries Tk framework is linked against with otool:

$ otool -L /System/Library/Frameworks/Tk.framework/Versions/8.4/Tk
/System/Library/Frameworks/Tk.framework/Versions/8.4/Tk:
        /System/Library/Frameworks/Tk.framework/Versions/8.4/Tk
           (compatibility version 8.4.0, current version 8.4.0)
        /System/Library/Frameworks/Tcl.framework/Versions/8.4/Tcl
           (compatibility version 8.4.0, current version 8.4.0)
        /System/Library/Frameworks/Carbon.framework/Versions/A/Carbon
           (compatibility version 2.0.0, current version 128.0.0)
        /System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices
           (compatibility version 1.0.0, current version 22.0.0)
        /usr/lib/libSystem.B.dylib
           (compatibility version 1.0.0, current version 88.0.0)

The WmHooks_Init function that calls wm_detect() above in the GDB
session, look like this:

void WmHooks_Init( Tcl_Interp * interp )
{
#ifndef WIN32
   Tk_Window   tkwin;
   Display   * dpy;

   tkwin = Tk_MainWindow(interp);
   if (tkwin != NULL)
   {
      dpy = Tk_Display(tkwin);
      if (dpy != NULL)
      {
         wm_detect(dpy);
      }
   }
#endif

   Tcl_CreateCommand(interp, "C_Wm_StayOnTop", WmHooks_StayOnTop,
(ClientData) NULL, NULL);
   Tcl_CreateCommand(interp, "C_Wm_SetIcon", WmHooks_SetIcon,
(ClientData) NULL, NULL);
}


Thanks for any helps, in advance.
Regards,
Roger