rapids_find_generate_module Support user code blocks

rapids-cmake/find/generate_module.cmake

@@ -34,6 +34,8 @@ Generate a Find*.cmake module for the requested package
                   [INCLUDE_SUFFIXES <suffixes...>]
                   [VERSION <version>]
                   [NO_CONFIG]
+                  [INITIAL_CODE_BLOCK <code_block_variable>]
+                  [FINAL_CODE_BLOCK <code_block_variable>]
                   [BUILD_EXPORT_SET <name>]
                   [INSTALL_EXPORT_SET <name>]
                   )
@@ -87,6 +89,20 @@ when installed.
   When provided will stop the generated Find Module from
   first searching for the projects shipped Find Config.
 
+``INITIAL_CODE_BLOCK``
+  Optional value of the variable that holds a string of code that will
+  be executed as the first step of this config file.
+
+  Note: This requires the code block variable instead of the contents
+  so that we can properly insert CMake code
+
+  ``FINAL_CODE_BLOCK``
+  Optional value of the variable that holds a string of code that will
+  be executed as the last step of this config file.
+
+  Note: This requires the code block variable instead of the contents
+  so that we can properly insert CMake code
+
 ``BUILD_EXPORT_SET``
   Record that this custom FindPackage module needs to be part
   of our build directory export set. This means that it will be
@@ -103,12 +119,34 @@ Result Variables
   :cmake:variable:`CMAKE_MODULE_PATH` will be modified to include the
   folder where `Find<PackageName>.cmake` is located.
 
+
+Example on how to properly use :cmake:command:`rapids_find_generate_module`:
+
+.. code-block:: cmake
+
+  ...
+
+  rapids_find_generate_module(
+    RDKAFKA
+    HEADER_NAMES rdkafkacpp.h
+    LIBRARY_NAMES rdkafka++
+    BUILD_EXPORT_SET consumer-exports
+    INSTALL_EXPORT_SET consumer-exports
+  )
+  rapids_find_package(
+    RDKAFKA REQUIRED
+    BUILD_EXPORT_SET consumer-exports
+    INSTALL_EXPORT_SET consumer-exports
+  )
+
+
 #]=======================================================================]
+# cmake-lint: disable=R0915
 function(rapids_find_generate_module name)
   list(APPEND CMAKE_MESSAGE_CONTEXT "rapids.find.generate_module")
 
   set(options NO_CONFIG)
-  set(one_value VERSION BUILD_EXPORT_SET INSTALL_EXPORT_SET)
+  set(one_value VERSION BUILD_EXPORT_SET INSTALL_EXPORT_SET INITIAL_CODE_BLOCK FINAL_CODE_BLOCK)
   set(multi_value HEADER_NAMES LIBRARY_NAMES INCLUDE_SUFFIXES)
   cmake_parse_arguments(_RAPIDS "${options}" "${one_value}" "${multi_value}" ${ARGN})
 
@@ -147,6 +185,21 @@ function(rapids_find_generate_module name)
     endif()
   endif()
 
+  if(DEFINED _RAPIDS_INITIAL_CODE_BLOCK)
+    if(NOT DEFINED ${_RAPIDS_INITIAL_CODE_BLOCK})
+      message(FATAL_ERROR "INITIAL_CODE_BLOCK variable `${_RAPIDS_INITIAL_CODE_BLOCK}` doesn't exist"
+      )
+    endif()
+    set(_RAPIDS_FIND_INITIAL_CODE_BLOCK "${${_RAPIDS_INITIAL_CODE_BLOCK}}")
+  endif()
+
+  if(DEFINED _RAPIDS_FINAL_CODE_BLOCK)
+    if(NOT DEFINED ${_RAPIDS_FINAL_CODE_BLOCK})
+      message(FATAL_ERROR "FINAL_CODE_BLOCK variable `${_RAPIDS_FINAL_CODE_BLOCK}` doesn't exist")
+    endif()
+    set(_RAPIDS_FIND_FINAL_CODE_BLOCK "${${_RAPIDS_FINAL_CODE_BLOCK}}")
+  endif()
+
   # Need to generate the module
   configure_file("${CMAKE_CURRENT_FUNCTION_LIST_DIR}/template/find_module.cmake.in"
                  "${CMAKE_BINARY_DIR}/cmake/find_modules/Find${name}.cmake" @ONLY)

rapids-cmake/find/template/find_module.cmake.in

@@ -45,6 +45,9 @@ This module will set the following variables in your project:
 #]=======================================================================]
 
 # Prefer using a Config module if it exists for this project
+
+@_RAPIDS_FIND_INITIAL_CODE_BLOCK@
+
 set(@_RAPIDS_PKG_NAME@_NO_CONFIG @_RAPIDS_NO_CONFIG@)
 if(NOT @_RAPIDS_PKG_NAME@_NO_CONFIG)
   find_package(@_RAPIDS_PKG_NAME@ CONFIG QUIET)
@@ -113,5 +116,7 @@ if(@_RAPIDS_PKG_NAME@_FOUND)
   endif()
 endif()
 
+@_RAPIDS_FIND_FINAL_CODE_BLOCK@
+
 unset(@_RAPIDS_PKG_NAME@_NO_CONFIG)
 unset(@_RAPIDS_PKG_NAME@_IS_HEADER_ONLY)

testing/find/CMakeLists.txt

@@ -1,5 +1,5 @@
 #=============================================================================
-# Copyright (c) 2021, NVIDIA CORPORATION.
+# Copyright (c) 2021-2023, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -40,3 +40,7 @@ add_cmake_config_test( find_package-version-required-explicit-failed.cmake SHOUL
 add_cmake_config_test( find_generate_module-build )
 add_cmake_config_test( find_generate_module-install )
 add_cmake_config_test( find_generate_module-header-only )
+
+add_cmake_config_test( find_generate_module-code-blocks )
+add_cmake_config_test( find_generate_module-back-initial-code-block-var.cmake SHOULD_FAIL "INITIAL_CODE_BLOCK variable `var_doesn't_exist` doesn't exist")
+add_cmake_config_test( find_generate_module-back-final-code-block-var.cmake SHOULD_FAIL "FINAL_CODE_BLOCK variable `var_doesn't_exist` doesn't exist")

testing/find/find_generate_module-back-final-code-block-var.cmake

@@ -0,0 +1,22 @@
+#=============================================================================
+# Copyright (c) 2023, 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}/find/generate_module.cmake)
+
+rapids_find_generate_module( RapidsTest
+    HEADER_NAMES rapids-cmake-test-header_only.hpp
+    FINAL_CODE_BLOCK   var_doesn't_exist
+    INSTALL_EXPORT_SET test_set
+    )

testing/find/find_generate_module-back-initial-code-block-var.cmake

@@ -0,0 +1,22 @@
+#=============================================================================
+# Copyright (c) 2023, 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}/find/generate_module.cmake)
+
+rapids_find_generate_module( RapidsTest
+    HEADER_NAMES rapids-cmake-test-header_only.hpp
+    INITIAL_CODE_BLOCK   var_doesn't_exist
+    INSTALL_EXPORT_SET test_set
+    )

testing/find/find_generate_module-code-blocks/CMakeLists.txt

@@ -0,0 +1,40 @@
+#=============================================================================
+# Copyright (c) 2023, 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(${rapids-cmake-dir}/find/generate_module.cmake)
+
+cmake_minimum_required(VERSION 3.23.1)
+project(rapids-test-project LANGUAGES CXX)
+
+set(CMAKE_PREFIX_PATH "${CMAKE_CURRENT_SOURCE_DIR}")
+
+# Generate the find module
+set(initial_code_block [[set(RapidsTest_INITIAL_CODE_BLOCK TRUE)]])
+set(final_code_block [[set(RapidsTest_FINAL_CODE_BLOCK TRUE)]])
+rapids_find_generate_module( RapidsTest
+    HEADER_NAMES rapids-cmake-test-header_only.hpp
+    INITIAL_CODE_BLOCK initial_code_block
+    FINAL_CODE_BLOCK   final_code_block
+    INSTALL_EXPORT_SET test_set
+    )
+
+find_package(RapidsTest REQUIRED)
+
+if(NOT RapidsTest_INITIAL_CODE_BLOCK)
+  message(FATAL_ERROR "RapidsTest_FOUND should be set to TRUE")
+endif()
+if(NOT RapidsTest_FINAL_CODE_BLOCK)
+  message(FATAL_ERROR "RAPIDSTEST_FOUND should be set to TRUE")
+endif()