warn about unused parameters, detect plugins with undefined symbols (disabled only on FreeBSD)

configure.ac

@@ -963,15 +963,17 @@ if test "${ac_cv_c_ntohl_sys_param_h}" != "no"; then
 fi
 CFLAGS="${CFLAGS_save}"
 
-RDC_PROG_CC_WFLAGS([all extra no-unused-parameter sign-compare undef pointer-arith bad-function-cast cast-align write-strings missing-prototypes volatile-register-var])
+RDC_PROG_CC_WFLAGS([all extra sign-compare undef pointer-arith bad-function-cast cast-align write-strings missing-prototypes volatile-register-var])
 RDC_PROG_CC_FLAGS_IFELSE([-pipe])
 
 dnl This helps detect broken plugins with undefined symbols
 dnl Better fail loudly at build-time than silenty at run-time.
 dnl Unfortunately, this sucks on FreeBSD (won't even link with -lc)
-dnl RDC_PROG_LINK_FLAGS_IFELSE([-Wl,-z,defs], [
-dnl   VLC_ADD_LDFLAGS([plugin],[-Wl,-z,defs])
-dnl ])
+if test `uname -s` != FreeBSD; then
+  RDC_PROG_LINK_FLAGS_IFELSE([-Wl,-z,defs], [
+    VLC_ADD_LDFLAGS([plugin],[-Wl,-z,defs])
+  ])
+fi
 
 dnl Check for various optimization flags
 AC_CACHE_CHECK([if \$CC accepts -Os],