Use dlsym to check if libdl is needed for plugin

config/plugins.m4 has

 if test "$plugins" = "yes"; then
    AC_SEARCH_LIBS([dlopen], [dl])
  fi

Plugin uses dlsym, but libasan.so only intercepts dlopen, not dlsym:

[hjl@gnu-tools-1 binutils-text]$ nm -D /lib64/libasan.so.4| grep " dl"
0000000000038580 W dlclose
                 U dl_iterate_phdr
000000000004dc50 W dlopen
                 U dlsym
                 U dlvsym
[hjl@gnu-tools-1 binutils-text]$

Testing dlopen for libdl leads to false negative when -fsanitize=address
is used.  It results in link failure:

../bfd/.libs/libbfd.a(plugin.o): undefined reference to symbol 'dlsym@@GLIBC_2.16'

dlsym should be used to check if libdl is needed for plugin.

bfd/

	PR gas/22318
	* configure: Regenerated.

binutils/

	PR gas/22318
	* configure: Regenerated.

gas/

	PR gas/22318
	* configure: Regenerated.

gprof/

	PR gas/22318
	* configure: Regenerated.

ld/

	PR gas/22318
	* configure: Regenerated.

10 files changed, 85 insertions, 60 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index c7fce7d..58ec0ce 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/22318
+	* configure: Regenerated.
+
 2018-04-05  Alan Modra  <amodra@gmail.com>
 
 	* elf-hppa.h (elf_hppa_info_to_howto): Init howto to NULL.
diff --git a/bfd/configure b/bfd/configure
index d1fe335..667f001 100755
--- a/bfd/configure
+++ b/bfd/configure
@@ -11828,9 +11828,9 @@ else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$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 :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -11843,11 +11843,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -11860,25 +11860,25 @@ for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index a577978..0d8bbc0 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/22318
+	* configure: Regenerated.
+
 2018-04-05  Maciej W. Rozycki  <macro@mips.com>
 
 	* testsuite/binutils-all/strip-13mips64.s: Use `.dc.l' rather
diff --git a/binutils/configure b/binutils/configure
index e11c43f..374605d 100755
--- a/binutils/configure
+++ b/binutils/configure
@@ -11622,9 +11622,9 @@ else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$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 :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -11637,11 +11637,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -11654,25 +11654,25 @@ for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
diff --git a/gas/ChangeLog b/gas/ChangeLog
index 17d1b17..f7dc5e5 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/22318
+	* configure: Regenerated.
+
 2018-04-04  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR binutils/23025
diff --git a/gas/configure b/gas/configure
index 73092c2..0504104 100755
--- a/gas/configure
+++ b/gas/configure
@@ -11383,9 +11383,9 @@ else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$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 :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -11398,11 +11398,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -11415,25 +11415,25 @@ for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
diff --git a/gprof/ChangeLog b/gprof/ChangeLog
index bfe1f27..da15c98 100644
--- a/gprof/ChangeLog
+++ b/gprof/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/22318
+	* configure: Regenerated.
+
 2018-03-01  Alan Modra  <amodra@gmail.com>
 
 	* configure.ac (ALL_LINGUAS): Add it, ro, ru, uk.  Sort.
diff --git a/gprof/configure b/gprof/configure
index 58e6b15..9b084cf 100755
--- a/gprof/configure
+++ b/gprof/configure
@@ -11298,9 +11298,9 @@ else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$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 :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -11313,11 +11313,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -11330,25 +11330,25 @@ for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 5ac7f53..b2fd135 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/22318
+	* configure: Regenerated.
+
 2018-04-05  Nick Clifton  <nickc@redhat.com>
 
 	PR 23030
diff --git a/ld/configure b/ld/configure
index fdefba2..1157299 100755
--- a/ld/configure
+++ b/ld/configure
@@ -15139,9 +15139,9 @@ else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$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 :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -15154,11 +15154,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -15171,25 +15171,25 @@ for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"