5 files changed, 13 insertions, 37 deletions
diff --git a/gr-uhd/include/gr_uhd_usrp_sink.h b/gr-uhd/include/gr_uhd_usrp_sink.h
index 557cb2cdb..0475957de 100644
--- a/gr-uhd/include/gr_uhd_usrp_sink.h
+++ b/gr-uhd/include/gr_uhd_usrp_sink.h
@@ -34,16 +34,10 @@ GR_UHD_API boost::shared_ptr<uhd_usrp_sink> uhd_make_usrp_sink(
     size_t num_channels
 );
 
-class GR_UHD_API uhd_usrp_sink : public gr_sync_block{
+class GR_UHD_API uhd_usrp_sink : virtual public gr_sync_block{
 public:
 
     /*!
-     * Set the IO signature for this block.
-     * \param sig the input signature
-     */
-    uhd_usrp_sink(gr_io_signature_sptr sig);
-
-    /*!
      * Set the subdevice specification.
      * \param spec the subdev spec markup string
      * \param mboard the motherboard index 0 to M-1
diff --git a/gr-uhd/include/gr_uhd_usrp_source.h b/gr-uhd/include/gr_uhd_usrp_source.h
index 3b36bf45d..038f9a91e 100644
--- a/gr-uhd/include/gr_uhd_usrp_source.h
+++ b/gr-uhd/include/gr_uhd_usrp_source.h
@@ -34,16 +34,10 @@ GR_UHD_API boost::shared_ptr<uhd_usrp_source> uhd_make_usrp_source(
     size_t num_channels
 );
 
-class GR_UHD_API uhd_usrp_source : public gr_sync_block{
+class GR_UHD_API uhd_usrp_source : virtual public gr_sync_block{
 public:
 
     /*!
-     * Set the IO signature for this block.
-     * \param sig the output signature
-     */
-    uhd_usrp_source(gr_io_signature_sptr sig);
-
-    /*!
      * Set the subdevice specification.
      * \param spec the subdev spec markup string
      * \param mboard the motherboard index 0 to M-1
diff --git a/gr-uhd/lib/Makefile.am b/gr-uhd/lib/Makefile.am
index d93b243e2..c27682f7f 100644
--- a/gr-uhd/lib/Makefile.am
+++ b/gr-uhd/lib/Makefile.am
@@ -37,6 +37,6 @@ libgnuradio_uhd_la_LIBADD = \
 	$(GNURADIO_CORE_LA) \
 	$(UHD_LIBS)
 
-libgnuradio_uhd_la_LDFLAGS = $(LTVERSIONFLAGS)
+libgnuradio_uhd_la_LDFLAGS = $(NO_UNDEFINED) $(LTVERSIONFLAGS)
 
 noinst_HEADERS =
diff --git a/gr-uhd/lib/gr_uhd_usrp_sink.cc b/gr-uhd/lib/gr_uhd_usrp_sink.cc
index b8b99a41a..d44af25ab 100644
--- a/gr-uhd/lib/gr_uhd_usrp_sink.cc
+++ b/gr-uhd/lib/gr_uhd_usrp_sink.cc
@@ -24,14 +24,6 @@
 #include <stdexcept>
 
 /***********************************************************************
- * UHD Multi USRP Sink
- **********************************************************************/
-uhd_usrp_sink::uhd_usrp_sink(gr_io_signature_sptr sig)
-:gr_sync_block("gr uhd usrp sink", sig, gr_make_io_signature(0, 0, 0)){
-    /* NOP */
-}
-
-/***********************************************************************
  * UHD Multi USRP Sink Impl
  **********************************************************************/
 class uhd_usrp_sink_impl : public uhd_usrp_sink{
@@ -41,9 +33,11 @@ public:
         const uhd::io_type_t &io_type,
         size_t num_channels
     ):
-        uhd_usrp_sink(gr_make_io_signature(
-            num_channels, num_channels, io_type.size
-        )),
+        gr_sync_block(
+            "gr uhd usrp sink",
+            gr_make_io_signature(num_channels, num_channels, io_type.size),
+            gr_make_io_signature(0, 0, 0)
+        ),
         _type(io_type),
         _nchan(num_channels),
         _has_time_spec(_nchan > 1)
diff --git a/gr-uhd/lib/gr_uhd_usrp_source.cc b/gr-uhd/lib/gr_uhd_usrp_source.cc
index 1234ed7fe..fed8e6624 100644
--- a/gr-uhd/lib/gr_uhd_usrp_source.cc
+++ b/gr-uhd/lib/gr_uhd_usrp_source.cc
@@ -26,14 +26,6 @@
 #include <boost/format.hpp>
 
 /***********************************************************************
- * UHD Multi USRP Source
- **********************************************************************/
-uhd_usrp_source::uhd_usrp_source(gr_io_signature_sptr sig)
-:gr_sync_block("gr uhd usrp source", gr_make_io_signature(0, 0, 0), sig){
-    /* NOP */
-}
-
-/***********************************************************************
  * UHD Multi USRP Source Impl
  **********************************************************************/
 class uhd_usrp_source_impl : public uhd_usrp_source{
@@ -43,9 +35,11 @@ public:
         const uhd::io_type_t &io_type,
         size_t num_channels
     ):
-        uhd_usrp_source(gr_make_io_signature(
-            num_channels, num_channels, io_type.size
-        )),
+        gr_sync_block(
+            "gr uhd usrp source",
+            gr_make_io_signature(0, 0, 0),
+            gr_make_io_signature(num_channels, num_channels, io_type.size)
+        ),
         _type(io_type),
         _nchan(num_channels),
         _stream_now(_nchan == 1),