Run AC_PROG_CXX only when needed.

Reported by Daniel Black <dragonheart@gentoo.org> in
<https://savannah.gnu.org/support/?106542>.

diff --git a/lib/m4/hooks.m4 b/lib/m4/hooks.m4
index 271919a663131d890c8758db5af14f2448c23c45..b07fa2f007baad7e59ecb02331ee11839b97cfb1 100644 (file)
--- a/lib/m4/hooks.m4
+++ b/lib/m4/hooks.m4
@@ -34,13 +34,12 @@ AC_DEFUN([LIBGNUTLS_HOOKS],
   SOVERSION=`expr ${LT_CURRENT} - ${LT_AGE}`
   AC_SUBST(SOVERSION)
 
-  AC_PROG_CXX
-
   AC_ARG_ENABLE(cxx,
                 AS_HELP_STRING([--disable-cxx],
                                [unconditionally disable the C++ library]),
                 use_cxx=$enableval, use_cxx=yes)
   if test "$use_cxx" != "no"; then
+    AC_PROG_CXX
     AC_LANG_PUSH(C++)
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])], use_cxx=yes, use_cxx=no)
     AC_LANG_POP(C++)