make rmw_implementation a meta rmw implementation

rmw_implementation/CMakeLists.txt

@@ -1,9 +1,15 @@
 cmake_minimum_required(VERSION 3.5)
 
-# must be not NONE since some rmw implementation require compiler checks
 project(rmw_implementation)
 
+if(NOT WIN32)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -Wall -Wextra")
+endif()
+
 find_package(ament_cmake REQUIRED)
+# provides FindPoco.cmake and Poco on platforms without it
+find_package(poco_vendor)
+find_package(Poco COMPONENTS Foundation)
 find_package(rmw_implementation_cmake REQUIRED)
 
 if(BUILD_TESTING)
@@ -13,17 +19,59 @@ endif()
 
 get_default_rmw_implementation(RMW_IMPLEMENTATION)
 
-get_available_rmw_implementations(impls)
+get_available_rmw_implementations(RMW_IMPLEMENTATIONS)
 message(STATUS "")
 message(STATUS "Found these rmw implementations:")
-foreach(impl IN LISTS impls)
+foreach(impl IN LISTS RMW_IMPLEMENTATIONS)
   message(STATUS "  '${impl}'")
 endforeach()
 
 message(STATUS "")
 message(STATUS "Using default rmw implementation: '${RMW_IMPLEMENTATION}'")
 message(STATUS "")
 
+# if only a single rmw impl. is available or poco is not available
+# this package will directly reference the default rmw impl.
+if(NOT RMW_IMPLEMENTATIONS MATCHES ";" OR NOT Poco_FOUND)
+  set(RMW_IMPLEMENTATION_SUPPORTS_POCO FALSE)
+
+else()
+  set(RMW_IMPLEMENTATION_SUPPORTS_POCO TRUE)
+  find_package(rmw REQUIRED)
+
+  message(STATUS "Support runtime override with any of the available rmw implementations")
+  message(STATUS "")
+  link_directories(${Poco_LIBRARY_DIR})
+  add_library(${PROJECT_NAME} SHARED
+    src/functions.cpp)
+  ament_target_dependencies(${PROJECT_NAME}
+    "Poco"
+    "rmw")
+  target_compile_definitions(${PROJECT_NAME}
+    PUBLIC "DEFAULT_RMW_IMPLEMENTATION=${RMW_IMPLEMENTATION}")
+  target_link_libraries(${PROJECT_NAME})
+  configure_rmw_library(${PROJECT_NAME})
+
+  ament_export_libraries(${PROJECT_NAME})
+  if(NOT WIN32)
+    ament_export_libraries(pthread)
+  endif()
+
+  install(
+    TARGETS ${PROJECT_NAME}
+    ARCHIVE DESTINATION lib
+    LIBRARY DESTINATION lib
+    RUNTIME DESTINATION bin
+  )
+endif()
+
+register_rmw_implementation(
+  "c:rosidl_typesupport_c"
+  "cpp:rosidl_typesupport_cpp"
+)
+
+# necessary since get_available_rmw_implementations excludes rmw_implementation
+list(APPEND RMW_IMPLEMENTATIONS "rmw_implementation")
 ament_package(
   CONFIG_EXTRAS "rmw_implementation-extras.cmake.in"
 )

rmw_implementation/package.xml

@@ -9,6 +9,10 @@
 
   <buildtool_depend>ament_cmake</buildtool_depend>
 
+  <build_depend>rmw</build_depend>
+
+  <depend>libpoco-dev</depend>
+  <depend>poco_vendor</depend>
   <depend>rmw_implementation_cmake</depend>
   <depend>rmw_connext_cpp</depend>
   <depend>rmw_connext_dynamic_cpp</depend>

rmw_implementation/rmw_implementation-extras.cmake.in

@@ -1,4 +1,4 @@
-# Copyright 2014-2015 Open Source Robotics Foundation, Inc.
+# Copyright 2014-2016 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.
@@ -16,38 +16,63 @@
 
 find_package(rmw_implementation_cmake REQUIRED)
 set(default_rmw_implementation "@RMW_IMPLEMENTATION@")
+set(available_rmw_implementations "@RMW_IMPLEMENTATIONS@")
 
 if(NOT "${RMW_IMPLEMENTATION}" STREQUAL "")
-  set(requested_default_rmw_implementation ${RMW_IMPLEMENTATION})
-  if(NOT requested_default_rmw_implementation STREQUAL default_rmw_implementation)
-    message(FATAL_ERROR
-      "The default RMW implementation has been specified as "
-      "'${requested_default_rmw_implementation}' through CMake,"
-      "however the default RMW implementation which will be used is "
-      "'${default_rmw_implementation}', which was specified when the "
-      "'rmw_implementation' package was built.")
+  set(requested_rmw_implementation ${RMW_IMPLEMENTATION})
+  if(@RMW_IMPLEMENTATION_SUPPORTS_POCO@)
+    if(NOT requested_rmw_implementation IN_LIST available_rmw_implementations)
+      message(FATAL_ERROR
+        "The RMW implementation has been specified as "
+        "'${requested_rmw_implementation}' through CMake, "
+        "however it is not in the list of supported rmw implementations, "
+        "which was specified when the 'rmw_implementation' package was built.")
+    endif()
+  else()
+    if(NOT requested_rmw_implementation STREQUAL default_rmw_implementation)
+      message(FATAL_ERROR
+        "The RMW implementation has been specified as "
+        "'${requested_rmw_implementation}' through CMake, "
+        "however this needs to match the RMW implementation "
+        "'${default_rmw_implementation}', "
+        "which was specified when the 'rmw_implementation' package was built.")
+    endif()
   endif()
 endif()
 
 if(NOT "$ENV{RMW_IMPLEMENTATION}" STREQUAL "")
-  set(requested_default_rmw_implementation $ENV{RMW_IMPLEMENTATION})
-  if(NOT requested_default_rmw_implementation STREQUAL default_rmw_implementation)
-    message(FATAL_ERROR
-      "The default RMW implementation has been specified as "
-      "'${requested_default_rmw_implementation}' "
-      "through the environment variable 'RMW_IMPLEMENTATION', "
-      "however the default RMW implementation which will be used is "
-      "'${default_rmw_implementation}', which was specified when the "
-      "'rmw_implementation' package was built.")
+  set(requested_rmw_implementation $ENV{RMW_IMPLEMENTATION})
+  if(@RMW_IMPLEMENTATION_SUPPORTS_POCO@)
+    if(NOT requested_rmw_implementation IN_LIST available_rmw_implementations)
+      message(FATAL_ERROR
+        "The RMW implementation has been specified as "
+        "'${requested_rmw_implementation}' through the environment variable "
+        "'RMW_IMPLEMENTATION', "
+        "however it is not in the list of supported rmw implementations, "
+        "which was specified when the 'rmw_implementation' package was built.")
+    endif()
+  else()
+    if(NOT requested_rmw_implementation STREQUAL default_rmw_implementation)
+      message(FATAL_ERROR
+        "The RMW implementation has been specified as "
+        "'${requested_rmw_implementation}' "
+        "through the environment variable 'RMW_IMPLEMENTATION', "
+        "however this needs to match the RMW implementation "
+        "'${default_rmw_implementation}', "
+        "which was specified when the 'rmw_implementation' package was built.")
+    endif()
   endif()
 endif()
 
-
-set(RMW_IMPLEMENTATION "${default_rmw_implementation}")
-message(STATUS "Using RMW implementation '${RMW_IMPLEMENTATION}' as default")
-find_package("${RMW_IMPLEMENTATION}" REQUIRED)
+if(@RMW_IMPLEMENTATION_SUPPORTS_POCO@)
+  set(selected_rmw_implementation "@PROJECT_NAME@")
+else()
+  set(selected_rmw_implementation "${default_rmw_implementation}")
+  message(STATUS "Using RMW implementation '${selected_rmw_implementation}' as default")
+endif()
+find_package("${selected_rmw_implementation}" REQUIRED)
 
 # TODO should never need definitions and include dirs?
-list(APPEND rmw_implementation_DEFINITIONS ${${RMW_IMPLEMENTATION}_DEFINITIONS})
-list(APPEND rmw_implementation_INCLUDE_DIRS ${${RMW_IMPLEMENTATION}_INCLUDE_DIRS})
-list(APPEND rmw_implementation_LIBRARIES ${${RMW_IMPLEMENTATION}_LIBRARIES})
+list(APPEND rmw_implementation_DEFINITIONS ${${selected_rmw_implementation}_DEFINITIONS})
+list(APPEND rmw_implementation_INCLUDE_DIRS ${${selected_rmw_implementation}_INCLUDE_DIRS})
+list(APPEND rmw_implementation_LIBRARIES ${${selected_rmw_implementation}_LIBRARIES})