- AC_CACHE_CHECK([whether we can use -ansi with gcc], [nmh_cv_has_dash_ansi],
- [nmh_saved_cppflags="$CPPFLAGS"
- nmh_saved_cflags="$CFLAGS"
- CPPFLAGS="-D_GNU_SOURCE"
- CFLAGS="-ansi -Wall -Werror"
- AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <time.h>],[tzset();])],
- [nmh_cv_has_dash_ansi=yes],
- [nmh_cv_has_dash_ansi=no])
- CPPFLAGS="$nmh_saved_cppflags"
- CFLAGS="$nmh_saved_cflags"])
- else
- nmh_cv_has_dash_ansi=no
+ AC_CACHE_CHECK([whether we can use -ansi with gcc], [nmh_cv_has_dash_ansi],
+ [nmh_saved_cppflags="$CPPFLAGS"
+ nmh_saved_cflags="$CFLAGS"
+ CPPFLAGS="-D_GNU_SOURCE"
+ CFLAGS="-ansi -Wall -Werror"
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <time.h>],[tzset();])],
+ [nmh_cv_has_dash_ansi=yes],
+ [nmh_cv_has_dash_ansi=no])
+ CPPFLAGS="$nmh_saved_cppflags"
+ CFLAGS="$nmh_saved_cflags"])
+
+ dnl Disable clang complaint about unused -ansi when linking.
+ AC_CACHE_CHECK([whether linker supports -Qunused-arguments],
+ [nmh_cv_has_q_unused_arguments],
+ [nmh_saved_ldflags="$LDFLAGS"
+ LDFLAGS="$LDFLAGS -Qunused-arguments"
+ AC_TRY_LINK([],[],nmh_cv_has_q_unused_arguments=yes,
+ nmh_cv_has_q_unused_arguments=no)
+ LDFLAGS="$nmh_saved_ldflags"])
+
+ if test "$nmh_cv_has_q_unused_arguments" = "yes"; then
+ test -z "$LDFLAGS" && LDFLAGS=-Qunused-arguments \
+ || LDFLAGS="$LDFLAGS -Qunused-arguments"