Fix rosbag2_py bug when using libc++

rosbag2_py/CMakeLists.txt

@@ -67,21 +67,21 @@ if(BUILD_TESTING)
   if(WIN32 AND "${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
     set(_PYTHON_EXECUTABLE "${PYTHON_EXECUTABLE_DEBUG}")
   endif()
-  set(pythonpath "${CMAKE_CURRENT_BINARY_DIR}/rosbag2_py;${CMAKE_CURRENT_SOURCE_DIR}")
-  if(NOT WIN32)
-    string(REPLACE ";" ":" pythonpath "${pythonpath}")
+  set(other_environment_vars)
+  if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    # Work around a rtti bug when using class_loader from a
+    # python extension built with libc++.
+    set(other_environment_vars "ROSBAG2_PY_TEST_WITH_RTLD_GLOBAL=True")
   endif()
   ament_add_pytest_test(test_sequential_reader_py "test/test_sequential_reader.py"
     PYTHON_EXECUTABLE "${_PYTHON_EXECUTABLE}"
-    APPEND_ENV "PYTHONPATH=${pythonpath}"
-    APPEND_LIBRARY_DIRS "${_append_library_dirs}"
-    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/resources"
+    APPEND_ENV
+      PYTHONPATH=${CMAKE_CURRENT_SOURCE_DIR}
+      ${other_environment_vars}
   )
   ament_add_pytest_test(test_sequential_writer_py "test/test_sequential_writer.py"
     PYTHON_EXECUTABLE "${_PYTHON_EXECUTABLE}"
-    APPEND_ENV "PYTHONPATH=${pythonpath}"
-    APPEND_LIBRARY_DIRS "${_append_library_dirs}"
-    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/resources"
+    APPEND_ENV "PYTHONPATH=${CMAKE_CURRENT_SOURCE_DIR}" ${other_environment_vars}
   )
 endif()
 

rosbag2_py/src/rosbag2_py/_reader.cpp

@@ -12,9 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <pybind11/pybind11.h>
-#include <pybind11/stl.h>
-
 #include <memory>
 #include <string>
 #include <vector>
@@ -27,6 +24,8 @@
 #include "rosbag2_storage/storage_filter.hpp"
 #include "rosbag2_storage/topic_metadata.hpp"
 
+#include "./pybind11.hpp"
+
 namespace rosbag2_py
 {
 

rosbag2_py/src/rosbag2_py/_storage.cpp

@@ -12,9 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <pybind11/pybind11.h>
-#include <pybind11/stl.h>
-
 #include <string>
 #include <vector>
 
@@ -23,6 +20,8 @@
 #include "rosbag2_storage/storage_filter.hpp"
 #include "rosbag2_storage/topic_metadata.hpp"
 
+#include "./pybind11.hpp"
+
 PYBIND11_MODULE(_storage, m) {
   m.doc() = "Python wrapper of the rosbag2 utilities API";
 

rosbag2_py/src/rosbag2_py/_writer.cpp

@@ -12,9 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <pybind11/pybind11.h>
-#include <pybind11/stl.h>
-
 #include <memory>
 #include <string>
 
@@ -27,6 +24,8 @@
 #include "rosbag2_storage/storage_filter.hpp"
 #include "rosbag2_storage/topic_metadata.hpp"
 
+#include "./pybind11.hpp"
+
 namespace rosbag2_py
 {
 

rosbag2_py/src/rosbag2_py/pybind11.hpp

@@ -0,0 +1,30 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ROSBAG2_PY__PYBIND11_HPP_
+#define ROSBAG2_PY__PYBIND11_HPP_
+
+// Ignore -Wunused-value for clang.
+// Based on https://github.com/pybind/pybind11/issues/2225
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-value"
+#endif
+#include <pybind11/pybind11.h>
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+#include <pybind11/stl.h>
+
+#endif  // ROSBAG2_PY__PYBIND11_HPP_

rosbag2_py/test/test_sequential_reader.py

@@ -12,15 +12,25 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
 from pathlib import Path
+import sys
 
-from common import get_rosbag_options
 from rcl_interfaces.msg import Log
 from rclpy.serialization import deserialize_message
-import rosbag2_py
 from rosidl_runtime_py.utilities import get_message
 from std_msgs.msg import String
 
+if os.environ.get('ROSBAG2_PY_TEST_WITH_RTLD_GLOBAL', None) is not None:
+    # This is needed on Linux when compiling with clang/libc++.
+    # TL;DR This makes class_loader work when using a python extension compiled with libc++.
+    #
+    # For the fun RTTI ABI details, see https://whatofhow.wordpress.com/2015/03/17/odr-rtti-dso/.
+    sys.setdlopenflags(os.RTLD_GLOBAL | os.RTLD_LAZY)
+
+from common import get_rosbag_options  # noqa
+import rosbag2_py  # noqa
+
 
 def test_sequential_reader():
     bag_path = str(Path(__file__).parent.parent / 'resources' / 'talker')

rosbag2_py/test/test_sequential_writer.py

@@ -12,12 +12,23 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from common import get_rosbag_options
+import os
+import sys
+
 from rclpy.serialization import deserialize_message, serialize_message
-import rosbag2_py
 from rosidl_runtime_py.utilities import get_message
 from std_msgs.msg import String
 
+if os.environ.get('ROSBAG2_PY_TEST_WITH_RTLD_GLOBAL', None) is not None:
+    # This is needed on Linux when compiling with clang/libc++.
+    # TL;DR This makes class_loader work when using a python extension compiled with libc++.
+    #
+    # For the fun RTTI ABI details, see https://whatofhow.wordpress.com/2015/03/17/odr-rtti-dso/.
+    sys.setdlopenflags(os.RTLD_GLOBAL | os.RTLD_LAZY)
+
+from common import get_rosbag_options  # noqa
+import rosbag2_py  # noqa
+
 
 def create_topic(writer, topic_name, topic_type, serialization_format='cdr'):
     """