gcc/config/plugins.m4
H.J. Lu 520a02b6fa 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.

	PR gas/22318
	* plugins.m4 (AC_PLUGINS): Use dlsym to check if libdl is needed.

From-SVN: r259140
2018-04-05 10:49:39 -07:00

22 lines
640 B
Plaintext

AC_DEFUN([AC_PLUGINS],
[
maybe_plugins=no
AC_CHECK_HEADERS([dlfcn.h], [maybe_plugins=yes], [], [AC_INCLUDES_DEFAULT])
AC_CHECK_HEADERS([windows.h], [maybe_plugins=yes], [], [AC_INCLUDES_DEFAULT])
AC_ARG_ENABLE([plugins],
AS_HELP_STRING([--enable-plugins], [Enable support for plugins]),
[case "${enableval}" in
no) plugins=no ;;
*) plugins=yes
if test "$maybe_plugins" != "yes" ; then
AC_MSG_ERROR([Building with plugin support requires a host that supports dlopen.])
fi ;;
esac],
[plugins=$maybe_plugins]
)
if test "$plugins" = "yes"; then
AC_SEARCH_LIBS([dlsym], [dl])
fi
])