[FFmpeg-devel] [PATCH] configure: check for dlsym as well

Timo Rothenpieler timo at rothenpieler.org
Thu Sep 1 12:23:33 EEST 2016

For some reason, when compiling with gcc-asan and a recent enough gcc
version(seen on 5.3+ so far), linking dlopen works without -ldl, but
dlsym fails with:

undefined reference to symbol 'dlsym@@GLIBC_2.2.5'

So this patchs checks for both dlopen and dlsym to work for determining
if -ldl is needed.
 configure | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 6741f83..a78edfa 100755
--- a/configure
+++ b/configure
@@ -5378,9 +5378,9 @@ check_code cc arm_neon.h "int16x8_t test = vdupq_n_s16(0)" && enable intrinsics_
 check_ldflags -Wl,--as-needed
 check_ldflags -Wl,-z,noexecstack
-if check_func dlopen; then
+if check_func dlopen && check_func dlsym; then
-elif check_func dlopen -ldl; then
+elif check_func dlopen -ldl && check_func dlsym -ldl; then

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