audio/audacity -latomic

Index: patches/patch-configure_ac
===================================================================
RCS file: /cvs/ports/audio/audacity/patches/patch-configure_ac,v
retrieving revision 1.2
diff -u -p -u -p -r1.2 patch-configure_ac
--- patches/patch-configure_ac 27 Mar 2019 16:19:55 -0000 1.2
+++ patches/patch-configure_ac 21 May 2019 12:44:52 -0000
@@ -1,21 +1,35 @@
$OpenBSD: patch-configure_ac,v 1.2 2019/03/27 16:19:55 jca Exp $

-- do not use -latomic with clang
+- check if -latomic is needed
+- disable jack

Index: configure.ac
--- configure.ac.orig
+++ configure.ac
-@@ -208,9 +208,6 @@ dnl Check if $CXX is clang by evaluating the version s
- dnl $ax_cv_cxx_compiler_vendor seems not to work (it is either "gnu" or just empty).
- dnl If $CXX is clang (string is found), grep returns 0 and the if is executed.
- dnl Use /dev/null to suppress grep output to shell.
+@@ -204,12 +204,16 @@ if test x$enable_universal_binary = xyes; then
+ esac
+ fi
+
+-dnl Check if $CXX is clang by evaluating the version string because
+-dnl $ax_cv_cxx_compiler_vendor seems not to work (it is either "gnu" or just empty).
+-dnl If $CXX is clang (string is found), grep returns 0 and the if is executed.
+-dnl Use /dev/null to suppress grep output to shell.
-if ($CXX --version | grep 'clang version' > /dev/null); then
- LDFLAGS="${LDFLAGS} -latomic"
--fi
++AC_LINK_IFELSE([AC_LANG_SOURCE([[
++ #include <atomic>
++ #include <cstdint>
++ std::atomic<std::int64_t> v;
++ int main() {
++ return v;
++ }
++]])], STD_ATOMIC_NEED_LIBATOMIC=no, STD_ATOMIC_NEED_LIBATOMIC=yes)
++if test "x$STD_ATOMIC_NEED_LIBATOMIC" = xyes; then
++ LDFLAGS="${LDFLAGS} -latomic"
+ fi

if test x$enable_sse = xyes; then
-
-@@ -650,10 +647,6 @@ case "${host_os}" in
+@@ -650,10 +654,6 @@ case "${host_os}" in
AC_CHECK_LIB(asound, snd_pcm_open, have_alsa=yes, have_alsa=no)
if [[ $have_alsa = "yes" ]] ; then
LIBS="$LIBS -lasound"
The diff below fixes linking on macppc.
Is there a better way to check if '-latomic' is needed?