From 6632e8ccecd8fe5de18ad78ced1c14755a24b169 Mon Sep 17 00:00:00 2001
From: Cary Coutant <ccoutant@google.com>
Date: Fri, 22 Nov 2013 15:46:51 -0800
Subject: [PATCH] Add check for which library is needed for dlopen.

gold/
	PR gold/16203
	* configure.ac: Add check for which library is needed for
	dlopen.
	* configure: Regenerate.
---
 gold/ChangeLog    |  6 +++++
 gold/configure    | 64 ++++++++++++++++++++++++++++++++++++++++++++---
 gold/configure.ac |  9 +++++--
 3 files changed, 74 insertions(+), 5 deletions(-)

diff --git a/gold/ChangeLog b/gold/ChangeLog
index c9dd0d9c5b8..2398b0f5555 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-22  Cary Coutant  <ccoutant@google.com>
+
+	* configure.ac: Add check for which library is needed for
+	dlopen.
+	* configure: Regenerate.
+
 2013-11-22  Cary Coutant  <ccoutant@google.com>
 
 	* testsuite/Makefile.am (exception_x86_64_bnd_test): Use in-tree
diff --git a/gold/configure b/gold/configure
index 83f5aa93082..24140cfec25 100755
--- a/gold/configure
+++ b/gold/configure
@@ -7193,13 +7193,71 @@ if test "x$ac_cv_header_dlfcn_h" = x""yes; then :
   cat >>confdefs.h <<_ACEOF
 #define HAVE_DLFCN_H 1
 _ACEOF
- DLOPEN_LIBS="-ldl"
-else
-  DLOPEN_LIBS=""
+
 fi
 
 done
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
+$as_echo_n "checking for library containing dlopen... " >&6; }
+if test "${ac_cv_search_dlopen+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dlopen ();
+int
+main ()
+{
+return dlopen ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' dl dld; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_cxx_try_link "$LINENO"; then :
+  ac_cv_search_dlopen=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if test "${ac_cv_search_dlopen+set}" = set; then :
+  break
+fi
+done
+if test "${ac_cv_search_dlopen+set}" = set; then :
+
+else
+  ac_cv_search_dlopen=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
+$as_echo "$ac_cv_search_dlopen" >&6; }
+ac_res=$ac_cv_search_dlopen
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+case "$ac_cv_search_dlopen" in
+  no*) DLOPEN_LIBS="";;
+  *)   DLOPEN_LIBS="$ac_cv_search_dlopen";;
+esac
 
 
 for ac_func in mallinfo posix_fallocate fallocate readv sysconf times
diff --git a/gold/configure.ac b/gold/configure.ac
index 82ad11ec625..9bc216b947c 100644
--- a/gold/configure.ac
+++ b/gold/configure.ac
@@ -528,9 +528,14 @@ AC_CHECK_HEADERS(ext/hash_map ext/hash_set)
 AC_CHECK_HEADERS(byteswap.h)
 
 dnl When plugins enabled dynamic loader interface is required. Check headers
-dnl which may provide this interface. In case of dlfcn.h add libdl to link.
+dnl which may provide this interface. Add the necessary library to link.
 AC_CHECK_HEADERS(windows.h)
-AC_CHECK_HEADERS(dlfcn.h, [DLOPEN_LIBS="-ldl"], [DLOPEN_LIBS=""])
+AC_CHECK_HEADERS(dlfcn.h)
+AC_SEARCH_LIBS(dlopen, [dl dld])
+case "$ac_cv_search_dlopen" in
+  no*) DLOPEN_LIBS="";;
+  *)   DLOPEN_LIBS="$ac_cv_search_dlopen";;
+esac
 AC_SUBST(DLOPEN_LIBS)
 
 AC_CHECK_FUNCS(mallinfo posix_fallocate fallocate readv sysconf times)
-- 
2.30.2