diff -purN -x CYGWIN-PATCHES -x 'aclocal.m4*' -x autom4te.cache -x config.cache -x config.log -x config.status -x config.h -x config.h.in -x ABOUT-NLS -x Makefile.in.in -x Makevars.template -x '*SlackBuild*' -x '*.egg-info' -x '*.class' -x '*.pyc' -x '*.mo' -x '*.gmo' -x '*.orig' -x '*.rej' -x '*.spec' -x '*.temp' -x '*~' -x '*.stackdump' -x COPYING -x INSTALL -x compile -x config-ml.in -x config.guess -x config.sub -x depcomp -x elisp-comp -x install-sh -x libtool.m4 -x ltoptions.m4 -x ltsugar.m4 -x ltversion.m4 -x 'lt~obsolete.m4' -x ltmain.sh -x mdate-sh -x missing -x mkinstalldirs -x py-compile -x symlink-tree -x texinfo.tex -x ylwrap -x config.rpath -x configure -x omf.make -x xmldocs.make -x gnome-doc-utils.make -x gnome-doc-utils.m4 -x intltool.m4 -x intltool-extract -x intltool-extract.in -x intltool-merge -x intltool-merge.in -x intltool-update -x intltool-update.in origsrc/gcc-4.3.0/gcc/config/i386/cygming-crtbegin.c src/gcc-4.3.0/gcc/config/i386/cygming-crtbegin.c
--- origsrc/gcc-4.3.0/gcc/config/i386/cygming-crtbegin.c	2007-07-05 08:07:34.000000000 +0100
+++ src/gcc-4.3.0/gcc/config/i386/cygming-crtbegin.c	2008-07-06 22:23:33.187500000 +0100
@@ -65,6 +65,12 @@ extern void _Jv_RegisterClasses (const v
 # define EH_FRAME_SECTION_CONST
 #endif
 
+/* We need to indirect through a variable, as gcc assumes
+ that a function label used as a constant is never zero.  */
+void (*register_frame_info_ptr) (const void *, struct object *) = __register_frame_info;
+void *(*deregister_frame_info_ptr) (const void *) = __deregister_frame_info;
+void (*jv_registerclasses_ptr) (const void *) = _Jv_RegisterClasses;
+
 /* Stick a label at the beginning of the frame unwind info so we can
    register/deregister it with the exception handling library code.  */
 #if DWARF2_UNWIND_INFO
@@ -93,15 +99,30 @@ __gcc_register_frame (void)
 /* Weak undefined symbols won't be pulled in from dlls; hence
    we first test if the dll is already loaded and, if so,
    get the symbol's address at run-time.  If the dll is not loaded,
-   fallback to weak linkage to static archive.  */
+   fallback to weak linkage to static archive.  Fallback also
+   if the DLL is loaded but does not export the routine.   */
 
-  void (*register_frame_fn) (const void *, struct object *);
+  void (*register_frame_fn) (const void *, struct object *) = 0;
   HANDLE h = GetModuleHandle (LIBGCC_SONAME);
   if (h)
     register_frame_fn = (void (*) (const void *, struct object *))
 			GetProcAddress (h, "__register_frame_info");
-  else 
-    register_frame_fn = __register_frame_info;
+  /* Can't use
+
+  if (!register_frame_fn)
+    register_frame_fn = register_frame_info_ptr;
+
+  directly, as gcc infers that the address of a function cannot
+  be zero, but in the case of an unlinked weak definition it can.
+  It would clearly be undefined code to use the address of an
+  unlinked weak function in a function call context, but I don't
+  know whether gcc is right to infer it's always non-zero when
+  being taken as a pointer-to-function constant.  */
+  if (!register_frame_fn)
+    register_frame_fn = register_frame_info_ptr;
+
+  /* We use weak references so as to not pull in all the EH machinery
+  unless it's actually required by something else in the final link.  */
   if (register_frame_fn)
      register_frame_fn (__EH_FRAME_BEGIN__, &obj);
 #endif
@@ -109,13 +130,13 @@ __gcc_register_frame (void)
 #if TARGET_USE_JCR_SECTION 
   if (__JCR_LIST__[0])
     {
-      void (*register_class_fn) (const void *);
+      void (*register_class_fn) (const void *) = 0;
       HANDLE h = GetModuleHandle (LIBGCJ_SONAME);
       if (h)
 	register_class_fn = (void (*) (const void *))
 			     GetProcAddress (h, "_Jv_RegisterClasses");
-      else
-	register_class_fn = _Jv_RegisterClasses;
+      if (!register_class_fn)
+	register_class_fn = jv_registerclasses_ptr;
 
       if (register_class_fn)
 	register_class_fn (__JCR_LIST__);
@@ -127,13 +148,13 @@ void
 __gcc_deregister_frame (void)
 {
 #if DWARF2_UNWIND_INFO
-  void *  (*deregister_frame_fn) (const void *);
+  void *  (*deregister_frame_fn) (const void *) = 0;
   HANDLE h = GetModuleHandle (LIBGCC_SONAME);
   if (h)
     deregister_frame_fn = (void* (*) (const void *))
 			  GetProcAddress (h, "__deregister_frame_info");
-  else 
-    deregister_frame_fn = __deregister_frame_info;
+  if (!deregister_frame_fn)
+    deregister_frame_fn = deregister_frame_info_ptr;
   if (deregister_frame_fn)
      deregister_frame_fn (__EH_FRAME_BEGIN__);
 #endif