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
