write_language now properly walks up the add_subdirectory call st…

…ack (#671)

Instead of assuming the filesystem directory layout matches `add_subdirectory` calls, we now walk the CMake
`PARENT_DIRECTORY` property.

This allows us to handle more custom layouts of CMake projects

Authors:
  - Robert Maynard (https://github.com/robertmaynard)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #671

rapids-cmake/export/write_language.cmake

@@ -1,5 +1,5 @@
 #=============================================================================
-# Copyright (c) 2021-2023, NVIDIA CORPORATION.
+# Copyright (c) 2021-2024, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -115,16 +115,14 @@ include("${CMAKE_BINARY_DIR}/cmake/PropagateCMake@[email protected]")
 # - Each directory but the root needs to include `PropagateCMake@[email protected]`
 # - Since the root directory doesn't have a parent it only needs to include
 #   `CMake@lang@Information`
+set(rapids_directories "${CMAKE_CURRENT_SOURCE_DIR}")
+get_directory_property(parent_dir DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}" PARENT_DIRECTORY)
+while(parent_dir)
+  list(APPEND rapids_directories "${parent_dir}")
+  get_directory_property(parent_dir DIRECTORY "${parent_dir}" PARENT_DIRECTORY)
+endwhile()
 
-set(rapids_directory "${CMAKE_CURRENT_SOURCE_DIR}")
-if(DEFINED CMAKE_CURRENT_FUNCTION)
-  string(APPEND rapids_directory "/fake_dir")
-endif()
-
-set(rapids_root_directory "${CMAKE_SOURCE_DIR}")
-cmake_path(GET rapids_directory PARENT_PATH rapids_directory)
-while(NOT rapids_directory STREQUAL rapids_root_directory)
-
+foreach(rapids_directory IN LISTS rapids_directories)
   # Make sure we haven't already installed a language hook for this directory
   # Once we found a directory with an existing hook we can safely stop
   # as that means hooks exist from that point up in the graph
@@ -136,20 +134,10 @@ while(NOT rapids_directory STREQUAL rapids_root_directory)
   else()
     break()
   endif()
-
-  cmake_path(GET rapids_directory PARENT_PATH rapids_directory)
-endwhile()
-
-# Make sure we haven't already installed a language hook for this directory
-cmake_language(DEFER DIRECTORY "${CMAKE_SOURCE_DIR}" GET_CALL_IDS rapids_existing_calls)
-if(NOT rapids_@lang@_hook IN_LIST rapids_existing_calls)
-  cmake_language(DEFER DIRECTORY "${CMAKE_SOURCE_DIR}"
-                 ID rapids_@lang@_hook
-                 CALL include "CMake@lang@Information")
-endif()
+endforeach()
 
 unset(rapids_existing_calls)
-unset(rapids_directory)
+unset(rapids_directories)
 unset(rapids_root_directory)
 ]=])
 

testing/export/write_language-nested-dirs/A/B/CMakeLists.txt

@@ -1,5 +1,5 @@
 #=============================================================================
-# Copyright (c) 2021, NVIDIA CORPORATION.
+# Copyright (c) 2021-2024, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,13 +16,6 @@
 
 include(${rapids-cmake-dir}/export/write_language.cmake)
 
-function(enable_nested_language file_path)
-  #replicates CPM including the file
-  include("${file_path}")
-endfunction()
-
-set(path "${CMAKE_CURRENT_BINARY_DIR}/enable_cuda_language.cmake")
-rapids_export_write_language(INSTALL CUDA "${path}")
-enable_nested_language("${path}")
+add_subdirectory(../C C)
 
 add_library(B STATIC static.cu)

testing/export/write_language-nested-dirs/A/C/CMakeLists.txt

@@ -0,0 +1,28 @@
+#=============================================================================
+# Copyright (c) 2021-2024, 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.
+#=============================================================================
+
+include(${rapids-cmake-dir}/export/write_language.cmake)
+
+function(enable_nested_language file_path)
+  #replicates CPM including the file
+  include("${file_path}")
+endfunction()
+
+set(path "${CMAKE_CURRENT_BINARY_DIR}/enable_cuda_language.cmake")
+rapids_export_write_language(INSTALL CUDA "${path}")
+enable_nested_language("${path}")
+
+add_library(C STATIC static.cu)

testing/export/write_language-nested-dirs/A/C/static.cu

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2021-2024, 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.
+ */
+
+static __global__ void example_cuda_kernel(int& r, int x, int y) { r = x * y + (x * 4 - (y / 2)); }
+
+int static_launch_kernelC(int x, int y)
+{
+  int r;
+  example_cuda_kernel<<<1, 1>>>(r, x, y);
+  return r;
+}