--- configure.in.orig	2018-03-02 20:59:11.000000000 +0800
+++ configure.in	2018-07-19 14:22:04.753721000 +0800
@@ -2573,7 +2573,7 @@
   AC_CACHE_CHECK(whether qsort_r is GNU version, rb_cv_gnu_qsort_r,
     [AC_TRY_COMPILE([
 @%:@include <stdlib.h>
-void qsort_r(void *base, size_t nmemb, size_t size,
+void (qsort_r)(void *base, size_t nmemb, size_t size,
 	    int (*compar)(const void *, const void *, void *),
 	    void *arg);
 ],[ ],
@@ -2583,7 +2583,7 @@
   AC_CACHE_CHECK(whether qsort_r is BSD version, rb_cv_bsd_qsort_r,
     [AC_TRY_COMPILE([
 @%:@include <stdlib.h>
-void qsort_r(void *base, size_t nmemb, size_t size,
+void (qsort_r)(void *base, size_t nmemb, size_t size,
 	     void *arg, int (*compar)(void *, const void *, const void *));
 ],[ ],
       [rb_cv_bsd_qsort_r=yes],
@@ -3423,7 +3423,7 @@
 			: ${LDSHARED='$(CC) -shared'}
 			if test "$rb_cv_binary_elf" = yes; then
 			    LDFLAGS="$LDFLAGS -rdynamic"
-			    DLDFLAGS="$DLDFLAGS "'-Wl,-soname,$@'
+			    DLDFLAGS="$DLDFLAGS "'-Wl,-E'
 			else
 			  test "$GCC" = yes && test "$rb_cv_prog_gnu_ld" = yes || LDSHARED='$(LD) -Bshareable'
 			fi
@@ -3896,6 +3895,7 @@
     [freebsd*|dragonfly*], [
 	SOLIBS='$(LIBS)'
 	LIBRUBY_SO='lib$(RUBY_SO_NAME).so.$(MAJOR)$(MINOR)'
+	RUBY_APPEND_OPTIONS(LIBRUBY_DLDFLAGS, ['-Wl,-soname,${LIBRUBY_SO}'])
 	if test "$rb_cv_binary_elf" != "yes" ; then
 	    LIBRUBY_SO="$LIBRUBY_SO.\$(TEENY)"
 	    LIBRUBY_ALIASES=''