Move IDLC to its own install component

This allows you to express a dependency on it as `find_package(CycloneDDS REQUIRED COMPONENTS idlc)`
Also added a warning if CycloneDDS was built with IDLC but IDLC is not requested.

Signed-off-by: Dan Rose <dan@digilabs.io>

cmake/Modules/Packaging.cmake

@@ -21,17 +21,10 @@ set(PACKAGING_MODULE_DIR "${PROJECT_SOURCE_DIR}/cmake/Modules/Packaging")
 set(CMAKE_INSTALL_CMAKEDIR "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}")
 
 # Generates <Package>Config.cmake.
-if(BUILD_IDLC)
+configure_package_config_file(
-  configure_package_config_file(
+  "${PACKAGING_MODULE_DIR}/PackageConfig.cmake.in"
-    "${PACKAGING_MODULE_DIR}/PackageConfig.cmake.in"
+  "${PROJECT_NAME}Config.cmake"
-    "${PROJECT_NAME}Config.cmake"
+  INSTALL_DESTINATION "${CMAKE_INSTALL_CMAKEDIR}")
-    INSTALL_DESTINATION "${CMAKE_INSTALL_CMAKEDIR}")
-else()
-  configure_package_config_file(
-    "${PACKAGING_MODULE_DIR}/PackageConfigNoIdlc.cmake.in"
-    "${PROJECT_NAME}Config.cmake"
-    INSTALL_DESTINATION "${CMAKE_INSTALL_CMAKEDIR}")
-endif()
 
 # Generates <Package>Version.cmake.
 write_basic_package_version_file(

cmake/Modules/Packaging/PackageConfig.cmake.in

@@ -12,4 +12,27 @@
 @PACKAGE_INIT@
 
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
-include("${CMAKE_CURRENT_LIST_DIR}/idlc/IdlcGenerate.cmake")
+option("@PROJECT_NAME@_IDLC_ALWAYS" "Should we include idlc even if the user didn't request the idlc component?" ON)
+
+set("@PROJECT_NAME@_idlc_FOUND" FALSE)
+if ("idlc" IN_LIST "@PROJECT_NAME@_FIND_COMPONENTS" OR "@PROJECT_NAME@_IDLC_ALWAYS")
+  include("${CMAKE_CURRENT_LIST_DIR}/idlc/IdlcGenerate.cmake" OPTIONAL RESULT_VARIABLE _IdlcGenerate)
+  if(NOT _IdlcGenerate STREQUAL "NOTFOUND")
+    set("@PROJECT_NAME@_idlc_FOUND" TRUE)
+  endif()
+endif()
+
+if ("${@PROJECT_NAME@_IDLC_ALWAYS}"
+  AND "${@PROJECT_NAME@_idlc_FOUND}"
+  AND (NOT "idlc" IN_LIST "@PROJECT_NAME@_FIND_COMPONENTS")
+)
+  message(AUTHOR_WARNING "\
+The IDL Compiler 'idlc' has not been requested but has been built is automatically included. \
+This will change in a future release. \
+If you need the idlc compiler, please add idlc to the COMPONENTS or OPTIONAL_COMPONENTS list in \
+find_package(@PROJECT_NAME@ ...). \
+If you don't need it, set the @PROJECT_NAME@_IDLC_ALWAYS=OFF to suppress this message .\
+")
+endif()
+
+check_required_components("@PROJECT_NAME@")

cmake/Modules/Packaging/PackageConfigNoIdlc.cmake.in

@@ -1,14 +0,0 @@
-#
-# Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
-#
-# This program and the accompanying materials are made available under the
-# terms of the Eclipse Public License v. 2.0 which is available at
-# http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
-# v. 1.0 which is available at
-# http://www.eclipse.org/org/documents/edl-v10.php.
-#
-# SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
-#
-@PACKAGE_INIT@
-
-include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")

src/idlc/CMakeLists.txt

@@ -46,16 +46,16 @@ include(cmake/IdlcGenerate.cmake)
 install(
   FILES "cmake/IdlcGenerate.cmake"
   DESTINATION "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}/idlc"
-  COMPONENT dev)
+  COMPONENT idlc)
 
 install(
   FILES "${IDLC_SCRIPT_IN}"
   DESTINATION "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}/idlc"
-  COMPONENT dev)
+  COMPONENT idlc)
 
 install(
   FILES "${IDLC_JAR}"
   DESTINATION "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}/idlc"
   PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_WRITE GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
-  COMPONENT dev)
+  COMPONENT idlc)