configure.in: PRELOADENV

* configure.in (PRELOADENV): platform specific environment to
  pre-load the given shared libraries.

* tool/runruby.rb: use config['PRELOADENV'] instead of hardcoded
  LD_PRELOAD.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.in

@@ -2972,6 +2972,7 @@ if test "$with_dln_a_out" != yes; then
 	[darwin*], [	: ${LDSHARED='$(CC) -dynamic -bundle'}
 			: ${LDFLAGS=""}
 			: ${LIBPATHENV=DYLD_LIBRARY_PATH}
+			: ${PRELOADENV=DYLD_INSERT_LIBRARIES}
 			rb_cv_dlopen=yes],
         [aix*], [	: ${LDSHARED='$(CC)'}
 			LDSHARED="$LDSHARED ${linker_flag}-G"
@@ -3080,6 +3081,7 @@ AC_SUBST(LINK_SO)
 AC_SUBST(LIBPATHFLAG)
 AC_SUBST(RPATHFLAG)
 AC_SUBST(LIBPATHENV, "${LIBPATHENV-LD_LIBRARY_PATH}")
+AC_SUBST(PRELOADENV, "${PRELOADENV-LD_PRELOAD}")
 AC_SUBST(TRY_LINK)
 
 if test "x$OPT_DIR" != x; then

tool/runruby.rb

@@ -79,8 +79,12 @@ if File.file?(libruby_so)
   if e = config['LIBPATHENV'] and !e.empty?
     env[e] = [abs_archdir, ENV[e]].compact.join(File::PATH_SEPARATOR)
   end
-  if /linux/ =~ RUBY_PLATFORM
-    env["LD_PRELOAD"] = [libruby_so, ENV["LD_PRELOAD"]].compact.join(' ')
+  if e = config['PRELOADENV']
+    e = nil if e.empty?
+    e ||= "LD_PRELOAD" if /linux/ =~ RUBY_PLATFORM
+  end
+  if e
+    env[e] = [libruby_so, ENV[e]].compact.join(' ')
   end
 end