Allow Compiling with CMake and C++03

This continues the work started in
OpenDDS#4481 and tries to correctly
handle C++ standards in all CMake support. Previously the CMake support
was agnostic towards C++ standards, but this meant that building with
CMake didn't have a way of differentiating C++ standards. Now we can
detect C++ standard support and should be able to build ACE/TAO
accordingly.

Also:
- Added `OPENDDS_CXX_STD_YEAR` CMake variable for easy checking of C++
  standard support.
- Passing C++ standard to the ACE/TAO MPC builds and
  `CMAKE_CXX_COMPILER` for gnuace builds.
- Removed need for `cmake/detect_ace.pl`
- Some of the changes originally in OpenDDS#4374
  - MPC location message will now say when it wasn't set.
  - Split adding of tests between different directories.

CMakeLists.txt

@@ -102,7 +102,7 @@ if(OPENDDS_XERCES3)
 endif()
 if(OPENDDS_SECURITY)
   add_subdirectory(dds/DCPS/security)
-  if(OPENDDS_BUILT_IN_TOPICS)
+  if(OPENDDS_BUILT_IN_TOPICS AND NOT OPENDDS_CXX_STD_YEAR LESS 2011)
     add_subdirectory(tools/dds/rtpsrelaylib)
     add_subdirectory(tools/rtpsrelay)
   endif()
@@ -158,48 +158,5 @@ if(OPENDDS_BUILD_EXAMPLES OR OPENDDS_BUILD_TESTS)
   add_subdirectory(DevGuideExamples/DCPS/Messenger)
 endif()
 if(OPENDDS_BUILD_TESTS)
-  find_package(GTest QUIET PATHS "${OPENDDS_GTEST}")
-  if(NOT GTest_FOUND)
-    set(gtestsm "${OPENDDS_SOURCE_DIR}/tests/googletest")
-    if(EXISTS "${gtestsm}/CMakeLists.txt")
-      message("GTest not found, using submodule")
-      set(fetch_args SOURCE_DIR "${gtestsm}")
-    else()
-      message("GTest not found, using clone")
-      set(fetch_args
-        GIT_REPOSITORY "https://github.com/OpenDDS/googletest"
-        GIT_TAG "v1.8.x"
-        GIT_SHALLOW TRUE
-        GIT_PROGRESS TRUE
-        USES_TERMINAL_DOWNLOAD TRUE
-      )
-    endif()
-    FetchContent_Declare(googletest ${fetch_args})
-    # Prevent overriding the parent project's compiler/linker
-    # settings on Windows
-    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
-    FetchContent_MakeAvailable(googletest)
-  endif()
-  if(TARGET GTest::gtest)
-    get_target_property(google_test_bin_dir GTest::gtest BINARY_DIR)
-    set(_OPENDDS_GOOGLE_TEST_DIR "${google_test_bin_dir}" CACHE INTERNAL "")
-  elseif(TARGET gtest)
-    get_target_property(google_test_bin_dir gtest BINARY_DIR)
-    set(_OPENDDS_GOOGLE_TEST_DIR "${google_test_bin_dir}" CACHE INTERNAL "")
-  endif()
-
-  add_subdirectory(tests/cmake/ace_tao_only)
-  if(OPENDDS_OWNERSHIP_PROFILE)
-    add_subdirectory(tests/cmake/Messenger)
-  endif()
-  add_subdirectory(tests/cmake/idl_compiler_tests)
-  add_subdirectory(tests/DCPS/Compiler/optional)
-  add_subdirectory(tests/cmake/include_subdir)
-  add_subdirectory(tests/DCPS/Compiler/char_literals)
-  add_subdirectory(tests/DCPS/HelloWorld)
-  # TODO: This test always builds shared libraries and linker complains about
-  # ACE/TAO libs lacking -fPIC when ACE is static.
-  if(OPENDDS_OWNERSHIP_PROFILE AND NOT OPENDDS_STATIC)
-    add_subdirectory(tests/cmake/generated_global)
-  endif()
+  add_subdirectory(tests)
 endif()

cmake/build_ace_tao.cmake

@@ -20,6 +20,9 @@ find_package(Perl REQUIRED)
 if(OPENDDS_STATIC)
   list(APPEND _OPENDDS_CONFIGURE_ACE_TAO_ARGS --static=1)
 endif()
+list(APPEND _OPENDDS_CONFIGURE_ACE_TAO_ARGS
+  --compiler "${CMAKE_CXX_COMPILER}"
+)
 execute_process(
   COMMAND
     "${PERL_EXECUTABLE}" "${_OPENDDS_CMAKE_DIR}/configure_ace_tao.pl"
@@ -35,6 +38,12 @@ execute_process(
   COMMAND_ERROR_IS_FATAL ANY
 )
 
+# Get the C++ standard OpenDDS is going to be built with. We are going to force
+# the ACE/TAO build to use the same standard.
+set(opendds_idl_std "$<TARGET_PROPERTY:opendds_idl,CXX_STANDARD>")
+set(dcps_std "$<TARGET_PROPERTY:OpenDDS_Dcps,CXX_STANDARD>")
+set(std "$<IF:$<TARGET_EXISTS:OpenDDS_Dcps>,${dcps_std},${opendds_idl_std}>")
+
 if(_OPENDDS_MPC_TYPE STREQUAL gnuace)
   execute_process(
     COMMAND
@@ -78,7 +87,7 @@ if(_OPENDDS_MPC_TYPE STREQUAL gnuace)
     SOURCE_DIR "${OPENDDS_ACE_TAO_SRC}"
     CONFIGURE_COMMAND "${CMAKE_COMMAND}" -E echo "Already configured"
     BUILD_IN_SOURCE TRUE
-    BUILD_COMMAND ${make_cmd}
+    BUILD_COMMAND ${make_cmd} "$<IF:$<BOOL:${std}>,opendds_cmake_std=-std=c++${std},>"
     BUILD_BYPRODUCTS ${byproducts}
     USES_TERMINAL_BUILD TRUE # Needed for Ninja to show the ACE/TAO build
     INSTALL_COMMAND "${CMAKE_COMMAND}" -E echo "No install step"
@@ -131,6 +140,7 @@ elseif(_OPENDDS_MPC_TYPE MATCHES "^vs")
       "${CMAKE_COMMAND}" -E env "ACE_ROOT=${OPENDDS_ACE}" "TAO_ROOT=${OPENDDS_TAO}"
       MSBuild "${sln}"
         "-property:Configuration=$<CONFIG>,Platform=${CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE}"
+        "$<IF:$<BOOL:${std}>,-property:LanguageStandard=stdcpp${std},>"
         "-maxcpucount"
     BUILD_BYPRODUCTS ${byproducts}
     USES_TERMINAL_BUILD TRUE # Needed for Ninja to show the ACE/TAO build

cmake/configure_ace_tao.pl

@@ -24,6 +24,7 @@
   workspace-file
   platform-macros-file
   static
+  compiler
 /;
 my %is_value_required = map {$_ => 1} @required_values;
 my %values = ();
@@ -100,6 +101,12 @@ sub read_file {
   my $platform_macros_path = "$values{ace}/include/makeinclude/platform_macros.GNU";
   open(my $platform_macros_file, '>', $platform_macros_path)
     or die("Failed to open $platform_macros_path: $!");
+  if ($values{compiler}) {
+    for my $var ('CC', 'CXX', 'LD') {
+      print $platform_macros_file ("$var = $values{compiler}\n");
+    }
+  }
+  print $platform_macros_file ("CCFLAGS += \$(opendds_cmake_std)\n");
   if ($values{'macro-line'}) {
     for my $line (@{$values{'macro-line'}}) {
       print $platform_macros_file ("$line\n");

cmake/cplusplus.cpp

@@ -0,0 +1,4 @@
+#if __cplusplus < OPENDDS_TEST_CPLUSPLUS
+#  error "Less then requested value"
+#endif
+int main() {}

cmake/import_common.cmake

@@ -360,6 +360,7 @@ function(_opendds_import_group_targets group libs exes)
 
     if(NOT TARGET ${target} AND ${var_prefix}_LIBRARY_FOUND)
       add_library(${target} ${OPENDDS_LIBRARY_TYPE} IMPORTED GLOBAL)
+      _opendds_cxx_std(${target} INTERFACE)
       set_target_properties(${target}
         PROPERTIES
           INTERFACE_INCLUDE_DIRECTORIES "${include_dirs}"
@@ -368,10 +369,6 @@ function(_opendds_import_group_targets group libs exes)
           INTERFACE_COMPILE_OPTIONS "${${var_prefix}_COMPILE_OPTIONS}"
       )
 
-      if(NOT CMAKE_VERSION VERSION_LESS "3.11.0" AND OPENDDS_CXX_STD)
-        target_compile_features(${target} INTERFACE "cxx_std_${OPENDDS_CXX_STD}")
-      endif()
-
       set(mpc_ext_proj_var "${group_prefix}_MPC_EXTERNAL_PROJECT")
       if(DEFINED "${mpc_ext_proj_var}")
         add_dependencies(${target} "${${mpc_ext_proj_var}}")