configure: Check separately for lib implementing dlopen and dlsym
Sometimes the library probiding dlopen is not the same one providing
dlsym.
This is the case when compiling with AddressSanitizer enabled. In this
case, AC_SEARCH_LIBS([dlopen]...) reports no lib is required, but tests
using dlsym still require to link against -ldl.
Change-Id: Ic619b0885688066b60c97caf1e2c7e5402c1d9f7
diff --git a/configure.ac b/configure.ac
index 7f2aabd..6f56176 100644
--- a/configure.ac
+++ b/configure.ac
@@ -58,8 +58,10 @@
AC_CHECK_HEADERS(execinfo.h sys/select.h sys/socket.h syslog.h ctype.h netinet/tcp.h)
# for src/conv.c
AC_FUNC_ALLOCA
-AC_SEARCH_LIBS([dlopen], [dl dld], [LIBRARY_DL="$LIBS";LIBS=""])
-AC_SUBST(LIBRARY_DL)
+AC_SEARCH_LIBS([dlopen], [dl dld], [LIBRARY_DLOPEN="$LIBS";LIBS=""])
+AC_SUBST(LIBRARY_DLOPEN)
+AC_SEARCH_LIBS([dlsym], [dl dld], [LIBRARY_DLSYM="$LIBS";LIBS=""])
+AC_SUBST(LIBRARY_DLSYM)
# for src/backtrace.c
AC_CHECK_LIB(execinfo, backtrace, BACKTRACE_LIB=-lexecinfo, BACKTRACE_LIB=)
AC_SUBST(BACKTRACE_LIB)