rapids_export_write_language no longer generates cmake dev warnings (#…

…712)

The `rapids_export_write_language` function would generate CMake code that would try and do `set(var PARENT_SCOPE)` in the root directory. This would cause CMake developer warnings to appear.

This resolves the issues by adding root level guards around the `set` commands, and setting up each rapids-cmake test to have developer warnings as errors.  Due to #680 we mark some tests with `NO_DEV_ERRORS` so that they continue to pass while we wait to 2025 to bump the minimum required CMake version.

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

Approvers:
  - Bradley Dice (https://github.com/bdice)

URL: #712

rapids-cmake/export/write_language.cmake

@@ -73,31 +73,33 @@ endif()
 #
 # So what we need to do is the following:
 #
-# 1. Transform each `set` in CMake@lang@Compiler to be a `PARENT_SCOPE`
-#    This allows us to propagate up immediate information that is
-#    used by commands such target_compile_features.
+# For non-root directories:
+#   1. Transform each `set` in CMake@lang@Compiler to be a `PARENT_SCOPE`
+#      This allows us to propagate up immediate information that is
+#      used by commands such target_compile_features.
 #
-# 2. Make sure that every directory including root also re-executes
-#    `CMake@lang@Information` This can't be deferred as the contents
-#    are required if any target is constructed
+#   2. Include `CMake@lang@Information` this can't be deferred as the contents
+#      are required if any target is constructed
+#
+# For root directories we only need to include `CMake@lang@Information`
 #
 
 # Expose the language at the current scope
 enable_language(@lang@)
 
-
 if(NOT EXISTS "${CMAKE_BINARY_DIR}/cmake/PropagateCMake@[email protected]")
   # 1.
   # Take everything that `enable_language` generated and transform all sets to PARENT_SCOPE ()
   # This will allow our parent directory to be able to call CMake@lang@Information
   file(STRINGS "${CMAKE_BINARY_DIR}/CMakeFiles/${CMAKE_VERSION}/CMake@[email protected]" rapids_code_to_transform)
-  set(rapids_code_to_execute )
+  set(rapids_code_to_execute "if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)\n")
   foreach( line IN LISTS rapids_code_to_transform)
     if(line MATCHES "[ ]*set")
       string(REPLACE ")" " PARENT_SCOPE)" line "${line}")
     endif()
     string(APPEND rapids_code_to_execute "${line}\n")
   endforeach()
+  string(APPEND rapids_code_to_execute "endif()\n")
 
   # 2.
   # Make sure we call "CMake@lang@Information" for the current directory

testing/cpm/CMakeLists.txt

@@ -15,6 +15,10 @@
 #=============================================================================
 add_cmake_config_test( rapids-cpm.cmake )
 
+# Do to https://github.com/rapidsai/rapids-cmake/issues/680 we need
+# to suppress dev warning as errors for all the rapids_cpm tests
+set(RAPIDS_TEST_DISABLE_DEV_ERRORS ON)
+
 add_cmake_config_test( cpm_find-add-pkg-source )
 add_cmake_config_test( cpm_find-and-find_package )
 add_cmake_config_test( cpm_find-components )
@@ -23,16 +27,16 @@ add_cmake_config_test( cpm_find-existing-target )
 add_cmake_config_test( cpm_find-existing-target-to-export-sets )
 add_cmake_config_test( cpm_find-gtest-no-gmock )
 add_cmake_config_test( cpm_find-options-escaped )
-add_cmake_config_test( cpm_find-patch-command NO_CPM_CACHE)
+add_cmake_config_test( cpm_find-patch-command NO_CPM_CACHE )
 add_cmake_config_test( cpm_find-patch-command-required NO_CPM_CACHE )
 add_cmake_config_test( cpm_find-patch-command-required-fails NO_CPM_CACHE SHOULD_FAIL "rapids-cmake [fmt]: failed to apply patch")
 add_cmake_config_test( cpm_find-restore-cpm-vars )
 add_cmake_config_test( cpm_find-version-explicit-install.cmake )
 
-add_cmake_build_test( cpm_generate_pins-format-patches NO_CPM_CACHE)
+add_cmake_build_test( cpm_generate_pins-format-patches NO_CPM_CACHE )
 add_cmake_build_test( cpm_generate_pins-nested )
 add_cmake_build_test( cpm_generate_pins-no-src-dir )
-add_cmake_build_test( cpm_generate_pins-override NO_CPM_CACHE)
+add_cmake_build_test( cpm_generate_pins-override NO_CPM_CACHE )
 add_cmake_build_test( cpm_generate_pins-pure-cpm )
 add_cmake_build_test( cpm_generate_pins-simple )
 add_cmake_build_test( cpm_generate_pins-simple-via-variable )

testing/test/CMakeLists.txt

@@ -46,7 +46,7 @@ add_cmake_build_test(install_relocatable-no-tests.cmake)
 add_cmake_build_test(install_relocatable-simple.cmake)
 add_cmake_build_test(install_relocatable-installed-tests-run)
 add_cmake_build_test(install_relocatable-installed-tests-run-lazy-msg)
-add_cmake_build_test(install_relocatable-with-gtest_discover_tests.cmake)
+add_cmake_build_test(install_relocatable-with-gtest_discover_tests.cmake NO_DEV_ERRORS)
 add_cmake_config_test(install_relocatable-wrong-component.cmake SHOULD_FAIL "${wrong_component_message}")
 
 add_cmake_ctest_test(add-impossible-allocation SHOULD_FAIL "Insufficient resources for test")

testing/utils/cmake_test.cmake

@@ -35,6 +35,7 @@ adds a test for each generator:
   add_cmake_build_test( (config|build|test|install)
                          <SourceOrDir>
                          [SERIAL]
+                         [NO_DEV_ERRORS]
                          [NO_CPM_CACHE]
                          [NO_RAPIDS_CMAKE_HOOKS]
                          [SHOULD_FAIL <expected error message string>]
@@ -60,7 +61,7 @@ adds a test for each generator:
 
 #]=======================================================================]
 function(add_cmake_test mode source_or_dir)
-  set(options SERIAL NO_CPM_CACHE NO_RAPIDS_CMAKE_HOOKS)
+  set(options SERIAL NO_DEV_ERRORS NO_CPM_CACHE NO_RAPIDS_CMAKE_HOOKS)
   set(one_value SHOULD_FAIL)
   set(multi_value)
   cmake_parse_arguments(RAPIDS_TEST "${options}" "${one_value}" "${multi_value}" ${ARGN})
@@ -84,7 +85,10 @@ function(add_cmake_test mode source_or_dir)
   endif()
 
   if(NOT RAPIDS_TEST_NO_RAPIDS_CMAKE_HOOKS)
-    set(extra_configure_flags "-DCMAKE_PROJECT_INCLUDE_BEFORE=${PROJECT_SOURCE_DIR}/utils/emulate_fetching_rapids_cmake.cmake")
+    list(APPEND extra_configure_flags "-DCMAKE_PROJECT_INCLUDE_BEFORE=${PROJECT_SOURCE_DIR}/utils/emulate_fetching_rapids_cmake.cmake")
+  endif()
+  if(NOT (RAPIDS_TEST_NO_DEV_ERRORS OR RAPIDS_TEST_DISABLE_DEV_ERRORS) )
+    list(APPEND extra_configure_flags "-Werror=dev")
   endif()
   if(DEFINED CPM_SOURCE_CACHE AND NOT RAPIDS_TEST_NO_CPM_CACHE)
     list(APPEND extra_configure_flags "-DCPM_SOURCE_CACHE=${CPM_SOURCE_CACHE}")