+void GC_with_callee_saves_pushed(fn, arg)
+void (*fn)();
+ptr_t arg;
+{
+ word dummy;
+
+# if defined(USE_GENERIC_PUSH_REGS)
+# ifdef HAVE_BUILTIN_UNWIND_INIT
+ /* This was suggested by Richard Henderson as the way to */
+ /* force callee-save registers and register windows onto */
+ /* the stack. */
+ __builtin_unwind_init();
+# else /* !HAVE_BUILTIN_UNWIND_INIT */
+# if defined(RS6000) || defined(POWERPC)
+ /* FIXME: RS6000 means AIX. */
+ /* This should probably be used in all Posix/non-gcc */
+ /* settings. We defer that change to minimize risk. */
+ ucontext_t ctxt;
+ getcontext(&ctxt);
+# else
+ /* Generic code */
+ /* The idea is due to Parag Patel at HP. */
+ /* We're not sure whether he would like */
+ /* to be he acknowledged for it or not. */
+ jmp_buf regs;
+ register word * i = (word *) regs;
+ register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
+
+ /* Setjmp doesn't always clear all of the buffer. */
+ /* That tends to preserve garbage. Clear it. */
+ for (; (char *)i < lim; i++) {
+ *i = 0;
+ }
+# if defined(MSWIN32) || defined(MSWINCE) \
+ || defined(UTS4) || defined(LINUX) || defined(EWS4800)
+ (void) setjmp(regs);
+# else
+ (void) _setjmp(regs);
+ /* We don't want to mess with signals. According to */
+ /* SUSV3, setjmp() may or may not save signal mask. */
+ /* _setjmp won't, but is less portable. */
+# endif
+# endif /* !AIX ... */
+# endif /* !HAVE_BUILTIN_UNWIND_INIT */
+# else
+# if defined(PTHREADS) && !defined(MSWIN32) /* !USE_GENERIC_PUSH_REGS */
+ /* We may still need this to save thread contexts. */
+ ucontext_t ctxt;
+ getcontext(&ctxt);
+# else /* Shouldn't be needed */
+ ABORT("Unexpected call to GC_with_callee_saves_pushed");
+# endif
+# endif
+# if (defined(SPARC) && !defined(HAVE_BUILTIN_UNWIND_INIT)) \
+ || defined(IA64)
+ /* On a register window machine, we need to save register */
+ /* contents on the stack for this to work. The setjmp */
+ /* is probably not needed on SPARC, since pointers are */
+ /* only stored in windowed or scratch registers. It is */
+ /* needed on IA64, since some non-windowed registers are */
+ /* preserved. */
+ {
+ GC_save_regs_ret_val = GC_save_regs_in_stack();
+ /* On IA64 gcc, could use __builtin_ia64_flushrs() and */
+ /* __builtin_ia64_flushrs(). The latter will be done */
+ /* implicitly by __builtin_unwind_init() for gcc3.0.1 */
+ /* and later. */
+ }
+# endif
+ fn(arg);
+ /* Strongly discourage the compiler from treating the above */
+ /* as a tail-call, since that would pop the register */
+ /* contents before we get a chance to look at them. */
+ GC_noop1((word)(&dummy));
+}
+