rapids-cmake can now be correctly used by multiple adjacent directories

CHANGELOG.md

@@ -13,6 +13,7 @@ Please see https://github.com/rapidsai/rapids-cmake/releases/tag/v21.08.0a for t
 ## 🐛 Bug Fixes
 - Add tests that verify all paths in each rapids-<component>.cmake file ([#24](https://github.com/rapidsai/rapids-cmake/pull/24))  [@robertmaynard](https://github.com/robertmaynard)
 - Correct issue where `rapids_export(DOCUMENTATION` content was being ignored([#30](https://github.com/rapidsai/rapids-cmake/pull/30))  [@robertmaynard](https://github.com/robertmaynard)
+- rapids-cmake can now be correctly used by multiple adjacent directories ([#33](https://github.com/rapidsai/rapids-cmake/pull/33))  [@robertmaynard](https://github.com/robertmaynard)
 
 
 # rapids-cmake 21.06.00 (Date TBD)

CMakeLists.txt

@@ -14,15 +14,26 @@
 # limitations under the License.
 #=============================================================================
 #
-# This is an entry point for other projects using rapids-cmake
-# Nothing should happen except setup to allow usage of the core components
+# This is an entry point for the vast majorty of projects using rapids-cmake.
+#
+# Unlike `init.cmake` this will setup the following cache variables:
+# - CMAKE_MODULE_PATH
+# - rapids-cmake-dir
+#
+# This is done to make sure that rapids-cmake can be properly included
+# multiple times by sibling projects without issue
 #
 
 # Enfore the minimum required CMake version for all users
 cmake_minimum_required(VERSION 3.20.1 FATAL_ERROR)
 
-# Hoist up this directory as a search path for CMake module
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake")
-set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH}" PARENT_SCOPE)
+if(NOT "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake" IN_LIST CMAKE_MODULE_PATH)
+  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake")
+  set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH}" CACHE PATH "" FORCE)
+  mark_as_advanced(CMAKE_MODULE_PATH)
+endif()
 
-set(rapids-cmake-dir "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake" PARENT_SCOPE)
+if(NOT DEFINED CACHE{rapids-cmake-dir})
+  set(rapids-cmake-dir "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake" CACHE PATH "" FORCE)
+  mark_as_advanced(rapids-cmake-dir)
+endif()

init.cmake

@@ -0,0 +1,27 @@
+#=============================================================================
+# Copyright (c) 2018-2021, NVIDIA CORPORATION.
+#
+# 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.
+#=============================================================================
+#
+# This is an entry point for other projects using rapids-cmake that
+# don't want any cache variables constructed
+#
+# Nothing should happen except setup to allow usage of the core components
+#
+
+# Hoist up this directory as a search path for CMake module
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake")
+set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH}")
+
+set(rapids-cmake-dir "${CMAKE_CURRENT_LIST_DIR}/rapids-cmake")

testing/CMakeLists.txt

@@ -27,3 +27,4 @@ add_subdirectory(cpm)
 add_subdirectory(cuda)
 add_subdirectory(export)
 add_subdirectory(find)
+add_subdirectory(other)

testing/other/CMakeLists.txt

@@ -0,0 +1,17 @@
+#=============================================================================
+# Copyright (c) 2018-2021, NVIDIA CORPORATION.
+#
+# 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.
+#=============================================================================
+
+add_cmake_config_test( verify_multiple_rapids_cmake_inclusions )

testing/other/verify_multiple_rapids_cmake_inclusions/A/CMakeLists.txt

@@ -0,0 +1,43 @@
+#=============================================================================
+# Copyright (c) 2018-2021, NVIDIA CORPORATION.
+#
+# 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.
+#=============================================================================
+
+# verify no rapids-cmake variables have been specified
+if(DEFINED rapids-cmake_SOURCE_DIR)
+  message(FATAL_ERROR "")
+endif()
+
+include(FetchContent)
+FetchContent_Declare(
+  rapids-cmake
+  SOURCE_DIR "${rapids-root-dir}"
+  )
+FetchContent_MakeAvailable(rapids-cmake)
+
+if(NOT DEFINED rapids-cmake_SOURCE_DIR)
+  message(FATAL_ERROR "expected variable rapids-cmake_SOURCE_DIR to exist")
+endif()
+
+if(NOT DEFINED rapids-cmake-dir)
+  message(FATAL_ERROR "expected variable rapids-cmake-dir to exist")
+endif()
+
+if(NOT "${rapids-cmake-dir}" IN_LIST CMAKE_MODULE_PATH)
+  message(FATAL_ERROR "expected variable rapids-cmake-dir to be inside CMAKE_MODULE_PATH")
+endif()
+
+if(NOT EXISTS "${rapids-cmake_SOURCE_DIR}/init.cmake")
+  message(FATAL_ERROR "")
+endif()

testing/other/verify_multiple_rapids_cmake_inclusions/B/CMakeLists.txt

@@ -0,0 +1,44 @@
+#=============================================================================
+# Copyright (c) 2018-2021, NVIDIA CORPORATION.
+#
+# 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.
+#=============================================================================
+
+# verify no rapids-cmake variables have been specified
+if(DEFINED rapids-cmake_SOURCE_DIR)
+  message(FATAL_ERROR "")
+endif()
+
+include(FetchContent)
+FetchContent_Declare(
+  rapids-cmake
+  SOURCE_DIR "${rapids-root-dir}"
+  )
+FetchContent_MakeAvailable(rapids-cmake)
+
+if(NOT DEFINED rapids-cmake_SOURCE_DIR)
+  message(FATAL_ERROR "")
+endif()
+
+if(NOT DEFINED rapids-cmake-dir)
+  message(FATAL_ERROR "")
+endif()
+
+if(NOT "${rapids-cmake-dir}" IN_LIST CMAKE_MODULE_PATH)
+  message(FATAL_ERROR "")
+endif()
+
+if(NOT EXISTS "${rapids-cmake_SOURCE_DIR}/init.cmake")
+  message(FATAL_ERROR "")
+endif()
+

testing/other/verify_multiple_rapids_cmake_inclusions/CMakeLists.txt

@@ -0,0 +1,26 @@
+#=============================================================================
+# Copyright (c) 2018-2021, NVIDIA CORPORATION.
+#
+# 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.
+#=============================================================================
+cmake_minimum_required(VERSION 3.20)
+project(rapids-test-project LANGUAGES CXX)
+
+cmake_path(GET rapids-cmake-dir PARENT_PATH rapids-root-dir)
+
+# Remove this cache variable so we can properly test
+# fetching rapids-cmake work as intended
+unset(rapids-cmake-dir CACHE)
+
+add_subdirectory(A)
+add_subdirectory(B)