Don't mix C and C++ libraries.

Now buildtests_c won't try to build C++ libraries.

Makefile

@@ -487,9 +487,9 @@ shared_cxx: dep_cxx libs/$(CONFIG)/libgrpc++.$(SHARED_EXT)
 
 privatelibs: privatelibs_c privatelibs_cxx
 
-privatelibs_c: dep_c libs/$(CONFIG)/libgpr_test_util.a libs/$(CONFIG)/libgrpc_test_util.a libs/$(CONFIG)/libgrpc++_test_util.a libs/$(CONFIG)/libend2end_fixture_chttp2_fake_security.a libs/$(CONFIG)/libend2end_fixture_chttp2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_with_oauth2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair_one_byte_at_a_time.a libs/$(CONFIG)/libend2end_test_cancel_after_accept.a libs/$(CONFIG)/libend2end_test_cancel_after_accept_and_writes_closed.a libs/$(CONFIG)/libend2end_test_cancel_after_invoke.a libs/$(CONFIG)/libend2end_test_cancel_before_invoke.a libs/$(CONFIG)/libend2end_test_cancel_in_a_vacuum.a libs/$(CONFIG)/libend2end_test_census_simple_request.a libs/$(CONFIG)/libend2end_test_disappearing_server.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_inflight_calls.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_tags.a libs/$(CONFIG)/libend2end_test_invoke_large_request.a libs/$(CONFIG)/libend2end_test_max_concurrent_streams.a libs/$(CONFIG)/libend2end_test_no_op.a libs/$(CONFIG)/libend2end_test_ping_pong_streaming.a libs/$(CONFIG)/libend2end_test_request_response_with_binary_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_trailing_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_simple_delayed_request.a libs/$(CONFIG)/libend2end_test_simple_request.a libs/$(CONFIG)/libend2end_test_thread_stress.a libs/$(CONFIG)/libend2end_test_writes_done_hangs_with_pending_read.a libs/$(CONFIG)/libend2end_certs.a
+privatelibs_c: dep_c libs/$(CONFIG)/libgpr_test_util.a libs/$(CONFIG)/libgrpc_test_util.a libs/$(CONFIG)/libend2end_fixture_chttp2_fake_security.a libs/$(CONFIG)/libend2end_fixture_chttp2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_with_oauth2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair_one_byte_at_a_time.a libs/$(CONFIG)/libend2end_test_cancel_after_accept.a libs/$(CONFIG)/libend2end_test_cancel_after_accept_and_writes_closed.a libs/$(CONFIG)/libend2end_test_cancel_after_invoke.a libs/$(CONFIG)/libend2end_test_cancel_before_invoke.a libs/$(CONFIG)/libend2end_test_cancel_in_a_vacuum.a libs/$(CONFIG)/libend2end_test_census_simple_request.a libs/$(CONFIG)/libend2end_test_disappearing_server.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_inflight_calls.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_tags.a libs/$(CONFIG)/libend2end_test_invoke_large_request.a libs/$(CONFIG)/libend2end_test_max_concurrent_streams.a libs/$(CONFIG)/libend2end_test_no_op.a libs/$(CONFIG)/libend2end_test_ping_pong_streaming.a libs/$(CONFIG)/libend2end_test_request_response_with_binary_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_trailing_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_simple_delayed_request.a libs/$(CONFIG)/libend2end_test_simple_request.a libs/$(CONFIG)/libend2end_test_thread_stress.a libs/$(CONFIG)/libend2end_test_writes_done_hangs_with_pending_read.a libs/$(CONFIG)/libend2end_certs.a
 
-privatelibs_cxx: dep_cxx libs/$(CONFIG)/libgpr_test_util.a libs/$(CONFIG)/libgrpc_test_util.a libs/$(CONFIG)/libgrpc++_test_util.a libs/$(CONFIG)/libend2end_fixture_chttp2_fake_security.a libs/$(CONFIG)/libend2end_fixture_chttp2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_simple_ssl_with_oauth2_fullstack.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair.a libs/$(CONFIG)/libend2end_fixture_chttp2_socket_pair_one_byte_at_a_time.a libs/$(CONFIG)/libend2end_test_cancel_after_accept.a libs/$(CONFIG)/libend2end_test_cancel_after_accept_and_writes_closed.a libs/$(CONFIG)/libend2end_test_cancel_after_invoke.a libs/$(CONFIG)/libend2end_test_cancel_before_invoke.a libs/$(CONFIG)/libend2end_test_cancel_in_a_vacuum.a libs/$(CONFIG)/libend2end_test_census_simple_request.a libs/$(CONFIG)/libend2end_test_disappearing_server.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_inflight_calls.a libs/$(CONFIG)/libend2end_test_early_server_shutdown_finishes_tags.a libs/$(CONFIG)/libend2end_test_invoke_large_request.a libs/$(CONFIG)/libend2end_test_max_concurrent_streams.a libs/$(CONFIG)/libend2end_test_no_op.a libs/$(CONFIG)/libend2end_test_ping_pong_streaming.a libs/$(CONFIG)/libend2end_test_request_response_with_binary_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_payload.a libs/$(CONFIG)/libend2end_test_request_response_with_trailing_metadata_and_payload.a libs/$(CONFIG)/libend2end_test_simple_delayed_request.a libs/$(CONFIG)/libend2end_test_simple_request.a libs/$(CONFIG)/libend2end_test_thread_stress.a libs/$(CONFIG)/libend2end_test_writes_done_hangs_with_pending_read.a libs/$(CONFIG)/libend2end_certs.a
+privatelibs_cxx: dep_cxx libs/$(CONFIG)/libgrpc++_test_util.a
 
 buildtests: buildtests_c buildtests_cxx
 

templates/Makefile.template

@@ -329,7 +329,7 @@ privatelibs: privatelibs_c privatelibs_cxx
 
 privatelibs_c: dep_c\
 % for lib in libs:
-% if lib.build == 'private':
+% if lib.build == 'private' and not lib.get('c++', False):
  libs/$(CONFIG)/lib${lib.name}.a\
 % endif
 % endfor
@@ -337,7 +337,7 @@ privatelibs_c: dep_c\
 
 privatelibs_cxx: dep_cxx\
 % for lib in libs:
-% if lib.build == 'private':
+% if lib.build == 'private' and lib.get('c++', False):
  libs/$(CONFIG)/lib${lib.name}.a\
 % endif
 % endfor