esac
+dnl These won't be used automatically yet. We also need to know, at least,
+dnl that the stack is continuous.
+AH_TEMPLATE(GC_SETJMP_WORKS, [Define if setjmp is known to save all
+ registers relevant for conservative garbage collection in the jmp_buf.])
+
+AH_TEMPLATE(GC_MARK_STACK, [Define to GC_USE_GCPROS_AS_BEFORE if
+ conservative garbage collection is not known to work.])
+
+
+case $opsys in
+ aix4-2 | hpux* | unixware)
+ dnl Conservative garbage collection has not been tested, so for now
+ dnl play it safe and stick with the old-fashioned way of marking.
+ AC_DEFINE(GC_MARK_STACK, [GC_USE_GCPROS_AS_BEFORE])
+ ;;
+
+ dnl Not all the architectures are tested, but there are Debian packages
+ dnl for SCM and/or Guile on them, so the technique must work. See also
+ dnl comments in alloc.c concerning setjmp and gcc.
+ dnl Fixme: it's probably safe to just use the GCC conditional below.
+ gnu-linux | gnu-kfreebsd )
+ AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[
+#if defined __i386__ || defined __sparc__ || defined __mc68000__ \
+ || defined __alpha__ || defined __mips__ || defined __s390__ \
+ || defined __arm__ || defined __powerpc__ || defined __amd64__ \
+ || defined __ia64__ || defined __sh__
+/* ok */
+#else
+# error "setjmp not known to work on this arch"
+#endif
+ ]], [[]])], AC_DEFINE(GC_SETJMP_WORKS, 1),
+ AC_DEFINE(GC_MARK_STACK, [GC_USE_GCPROS_AS_BEFORE]) )
+ ;;
+esac
+
+
+if test x$GCC = xyes; then
+ dnl GC_SETJMP_WORKS is nearly always appropriate for GCC.
+ AC_DEFINE(GC_SETJMP_WORKS, 1)
+else
+ case $opsys in
+ dnl irix: Tested on Irix 6.5. SCM worked on earlier versions.
+ freebsd | netbsd | openbsd | irix6-5 | sol2* )
+ AC_DEFINE(GC_SETJMP_WORKS, 1)
+ ;;
+ esac
+fi dnl GCC?
+
+
dnl Used in xfaces.c.
case $opsys in
hpux* | sol2* )
#undef noinline
#endif
-/* These won't be used automatically yet. We also need to know, at least,
- that the stack is continuous. */
-#ifdef __GNUC__
-# ifndef GC_SETJMP_WORKS
- /* GC_SETJMP_WORKS is nearly always appropriate for GCC. */
-# define GC_SETJMP_WORKS 1
-# endif
-#endif
-
#endif /* EMACS_CONFIG_H */
/*