Refactor rapids_export_post_find and rapids_export_find_package_root

These commands now offer a syntax that allows termination
based on no export set being given, or a external condition
variable.

rapids-cmake/cpm/libcudacxx.cmake

@@ -101,18 +101,14 @@ function(rapids_cpm_libcudacxx)
   set(multi_value)
   cmake_parse_arguments(_RAPIDS "${options}" "${one_value}" "${multi_value}" ${ARGN})
 
-  if(libcudacxx_SOURCE_DIR AND _RAPIDS_BUILD_EXPORT_SET)
+  if(libcudacxx_SOURCE_DIR)
     # Store where CMake can find our custom libcudacxx
     include("${rapids-cmake-dir}/export/find_package_root.cmake")
-    rapids_export_find_package_root(BUILD libcudacxx "${libcudacxx_SOURCE_DIR}/lib/cmake"
-                                    ${_RAPIDS_BUILD_EXPORT_SET})
-  endif()
-
-  if(libcudacxx_SOURCE_DIR AND to_install)
-    include("${rapids-cmake-dir}/export/find_package_root.cmake")
+    rapids_export_find_package_root(BUILD libcudacxx "${libcudacxx_SOURCE_DIR}/lib/cmake" FOR
+                                    EXPORT_SET ${_RAPIDS_BUILD_EXPORT_SET})
     rapids_export_find_package_root(INSTALL libcudacxx
                                     [=[${CMAKE_CURRENT_LIST_DIR}/../../rapids/cmake/libcudacxx]=]
-                                    ${_RAPIDS_INSTALL_EXPORT_SET})
+                                    EXPORT_SET ${_RAPIDS_INSTALL_EXPORT_SET} CONDITION to_install)
   endif()
 
   # Propagate up variables that CPMFindPackage provide

rapids-cmake/cpm/nvcomp.cmake

@@ -173,9 +173,8 @@ function(rapids_cpm_nvcomp)
     install(FILES "${nvcomp_ROOT}/LICENSE" DESTINATION info/ RENAME NVCOMP_LICENSE)
   endif()
 
-  if(_RAPIDS_BUILD_EXPORT_SET AND nvcomp_proprietary_binary)
-    # point our consumers to where they can find the pre-built version
-    rapids_export_find_package_root(BUILD nvcomp "${nvcomp_ROOT}" ${_RAPIDS_BUILD_EXPORT_SET})
-  endif()
+  # point our consumers to where they can find the pre-built version
+  rapids_export_find_package_root(BUILD nvcomp "${nvcomp_ROOT}" EXPORT_SET
+                                  ${_RAPIDS_BUILD_EXPORT_SET} CONDITION nvcomp_proprietary_binary)
 
 endfunction()

rapids-cmake/cpm/thrust.cmake

@@ -100,24 +100,20 @@ function(rapids_cpm_thrust NAMESPACE namespaces_name)
   set(post_find_code "if(NOT TARGET ${namespaces_name}::Thrust)"
                      "  thrust_create_target(${namespaces_name}::Thrust FROM_OPTIONS)" "endif()")
 
-  if(Thrust_SOURCE_DIR AND _RAPIDS_BUILD_EXPORT_SET)
+  if(Thrust_SOURCE_DIR)
     # Store where CMake can find the Thrust-config.cmake that comes part of Thrust source code
     include("${rapids-cmake-dir}/export/find_package_root.cmake")
     include("${rapids-cmake-dir}/export/detail/post_find_package_code.cmake")
-    rapids_export_find_package_root(BUILD Thrust "${Thrust_SOURCE_DIR}/cmake"
+    rapids_export_find_package_root(BUILD Thrust "${Thrust_SOURCE_DIR}/cmake" EXPORT_SET
                                     ${_RAPIDS_BUILD_EXPORT_SET})
-    rapids_export_post_find_package_code(BUILD Thrust "${post_find_code}"
+    rapids_export_post_find_package_code(BUILD Thrust "${post_find_code}" EXPORT_SET
                                          ${_RAPIDS_BUILD_EXPORT_SET})
-  endif()
 
-  if(Thrust_SOURCE_DIR AND _RAPIDS_INSTALL_EXPORT_SET AND to_install)
-    include("${rapids-cmake-dir}/export/find_package_root.cmake")
-    include("${rapids-cmake-dir}/export/detail/post_find_package_code.cmake")
     rapids_export_find_package_root(INSTALL Thrust
                                     [=[${CMAKE_CURRENT_LIST_DIR}/../../rapids/cmake/thrust]=]
-                                    ${_RAPIDS_INSTALL_EXPORT_SET})
-    rapids_export_post_find_package_code(INSTALL Thrust "${post_find_code}"
-                                         ${_RAPIDS_INSTALL_EXPORT_SET})
+                                    EXPORT_SET ${_RAPIDS_INSTALL_EXPORT_SET} CONDITION to_install)
+    rapids_export_post_find_package_code(INSTALL Thrust "${post_find_code}" EXPORT_SET
+                                         ${_RAPIDS_INSTALL_EXPORT_SET} CONDITION to_install)
   endif()
 
   # Check for the existence of thrust_create_target so we support fetching Thrust with DOWNLOAD_ONLY

rapids-cmake/export/detail/post_find_package_code.cmake

@@ -29,8 +29,9 @@ has ben found successfully.
   rapids_export_post_find_package_code((BUILD|INSTALL)
                                        <PackageName>
                                        <code>
-                                       <ExportSet>
-                                        )
+                                       (<ExportSetName> | EXPORT_SET [ExportSetName])
+                                       [CONDITION <variableName>]
+                                       )
 
 When using complicated find modules like `Thrust` you might need to run some code after
 execution. Multiple calls to :cmake:command:`rapids_export_post_find_package_code` will append the
@@ -47,11 +48,33 @@ instructions to execute in call order.
   Record code to be executed immediately after `PackageName` has been found
   for our our install directory export set.
 
+``EXPORT_SET``
+  List the export set name that this code should be attached too. If
+  no name is given the associated call will be ignored.
+
+``CONDITION``
+  A boolean variable name, that when evaluates to undefined or a false value
+  will cause the associated call to be ignored.
+
 #]=======================================================================]
-function(rapids_export_post_find_package_code type name code export_set)
+function(rapids_export_post_find_package_code type name code)
   list(APPEND CMAKE_MESSAGE_CONTEXT "rapids.export.post_find_package_code")
 
+  set(options "")
+  set(one_value EXPORT_SET CONDITION)
+  set(multi_value "")
+  cmake_parse_arguments(_RAPIDS "${options}" "${one_value}" "${multi_value}" ${ARGN})
+  # handle when we are given just an export set name and not `EXPORT_SET <name>`
+  if(_RAPIDS_UNPARSED_ARGUMENTS AND NOT _RAPIDS_COMPONENTS_EXPORT_SET)
+    set(_RAPIDS_EXPORT_SET ${_RAPIDS_UNPARSED_ARGUMENTS})
+  endif()
+  # Early terminate conditions
+  if(NOT _RAPIDS_EXPORT_SET OR NOT ${_RAPIDS_CONDITION})
+    return()
+  endif()
+
   string(TOLOWER ${type} type)
+  set(export_set ${_RAPIDS_EXPORT_SET})
 
   if(NOT TARGET rapids_export_${type}_${export_set})
     add_library(rapids_export_${type}_${export_set} INTERFACE)

rapids-cmake/export/find_package_root.cmake

@@ -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.
@@ -29,7 +29,8 @@ needs to be set to the provided path.
   rapids_export_find_package_root( (BUILD|INSTALL)
                                    <PackageName>
                                    <directory_path>
-                                   <ExportSet>
+                                   (<ExportSetName> | EXPORT_SET [ExportSetName])
+                                   [CONDITION <variableName>]
                                    )
 
 When constructing complicated export sets, espically ones that
@@ -47,11 +48,33 @@ will find the packaged dependency.
   before any find_dependency calls for `PackageName` for our install directory
   export set.
 
+``EXPORT_SET``
+  List the export set name that this code should be attached too. If
+  no name is given the associated call will be ignored.
+
+``CONDITION``
+  A boolean variable name, that when evaluates to undefined or a false value
+  will cause the associated call to be ignored.
+
 #]=======================================================================]
-function(rapids_export_find_package_root type name dir_path export_set)
+function(rapids_export_find_package_root type name dir_path)
   list(APPEND CMAKE_MESSAGE_CONTEXT "rapids.export.find_package_root_dir")
 
+  set(options "")
+  set(one_value EXPORT_SET CONDITION)
+  set(multi_value "")
+  cmake_parse_arguments(_RAPIDS "${options}" "${one_value}" "${multi_value}" ${ARGN})
+  # handle when we are given just an export set name and not `EXPORT_SET <name>`
+  if(_RAPIDS_UNPARSED_ARGUMENTS AND NOT _RAPIDS_COMPONENTS_EXPORT_SET)
+    set(_RAPIDS_EXPORT_SET ${_RAPIDS_UNPARSED_ARGUMENTS})
+  endif()
+  # Early terminate conditions
+  if(NOT _RAPIDS_EXPORT_SET OR NOT ${_RAPIDS_CONDITION})
+    return()
+  endif()
+
   string(TOLOWER ${type} type)
+  set(export_set ${_RAPIDS_EXPORT_SET})
 
   if(NOT TARGET rapids_export_${type}_${export_set})
     add_library(rapids_export_${type}_${export_set} INTERFACE)

rapids-cmake/export/write_dependencies.cmake

@@ -89,14 +89,12 @@ endif()\n")
     endif()
   endif()
 
-  if(find_root_dirs)
-    foreach(package IN LISTS find_root_dirs)
-      get_property(root_dir_path TARGET rapids_export_${type}_${export_set}
-                   PROPERTY "FIND_ROOT_FOR_${package}")
-      set(dep_content "set(${package}_ROOT \"${root_dir_path}\")")
-      string(APPEND _RAPIDS_EXPORT_CONTENTS "${dep_content}\n")
-    endforeach()
-  endif()
+  foreach(package IN LISTS find_root_dirs)
+    get_property(root_dir_path TARGET rapids_export_${type}_${export_set}
+                 PROPERTY "FIND_ROOT_FOR_${package}")
+    set(dep_content "set(${package}_ROOT \"${root_dir_path}\")")
+    string(APPEND _RAPIDS_EXPORT_CONTENTS "${dep_content}\n")
+  endforeach()
 
   if(find_modules)
     cmake_path(GET file_path PARENT_PATH find_module_dest)

testing/export/write_dependencies-root-dirs.cmake

@@ -19,6 +19,9 @@ include(${rapids-cmake-dir}/export/write_dependencies.cmake)
 rapids_export_find_package_root(BUILD RMM [=[${CMAKE_CURRENT_LIST_DIR}/fake/build/path]=] test_set)
 rapids_export_write_dependencies(build test_set "${CMAKE_CURRENT_BINARY_DIR}/build_export_set.cmake")
 
+rapids_export_find_package_root(BUILD RMM "/bad/install/path" EXPORT_SET ${unknown_var}) #ignored
+rapids_export_find_package_root(BUILD RMM "/bad/install/path2" EXPORT_SET test_set CONDITION unknown_var) #ignored
+
 # Parse the `build_export_set.cmake` file for correct escaped args
 # to `rapids_export_find_package_root` calls
 set(build_to_match_string [=[set(RMM_ROOT "${CMAKE_CURRENT_LIST_DIR}/fake/build/path"]=])
@@ -28,8 +31,11 @@ if(is_found EQUAL -1)
   message(FATAL_ERROR "rapids_export_write_dependencies(BUILD) failed to preserve variables in the directory path to rapids_export_find_package_root")
 endif()
 
-rapids_export_find_package_root(install RMM "/first/install/path" test_set)
+rapids_export_find_package_root(install RMM "/first/install/path" EXPORT_SET test_set)
 rapids_export_find_package_root(INSTALL RMM "/second/install/path" test_set)
+set(to_install FALSE)
+rapids_export_find_package_root(INSTALL RMM "/bad/install/path" EXPORT_SET test_set CONDITION to_install) #ignored
+
 rapids_export_find_package_root(install PKG2 "/pkg2/install/path" test_set)
 rapids_export_write_dependencies(INSTALL test_set "${CMAKE_CURRENT_BINARY_DIR}/install_export_set.cmake")