[runtimes][CMake] Simplify the propagation of test dependencies (#93558)

Instead of using FOO_TEST_DEPS global variables that don't get updated
properly from subdirectories, use targets to propagate the dependencies
across directories.

libcxx/CMakeLists.txt

@@ -856,15 +856,14 @@ endfunction()
 #===============================================================================
 # Setup Source Code And Tests
 #===============================================================================
+add_custom_target(cxx-test-depends
+  COMMENT "Build dependencies required to run the libc++ test suite.")
+
 add_subdirectory(include)
 add_subdirectory(src)
 add_subdirectory(utils)
 add_subdirectory(modules)
 
-set(LIBCXX_TEST_DEPS "cxx_experimental")
-
-list(APPEND LIBCXX_TEST_DEPS generate-cxx-modules)
-
 if (LIBCXX_INCLUDE_BENCHMARKS)
   add_subdirectory(benchmarks)
 endif()

libcxx/benchmarks/CMakeLists.txt

@@ -252,10 +252,6 @@ endforeach()
 if (LIBCXX_INCLUDE_TESTS)
   include(AddLLVM)
 
-  if (NOT DEFINED LIBCXX_TEST_DEPS)
-    message(FATAL_ERROR "Expected LIBCXX_TEST_DEPS to be defined")
-  endif()
-
   configure_lit_site_cfg(
           ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
           ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py)
@@ -265,6 +261,6 @@ if (LIBCXX_INCLUDE_TESTS)
   add_lit_target(check-cxx-benchmarks
           "Running libcxx benchmarks tests"
           ${CMAKE_CURRENT_BINARY_DIR}
-          DEPENDS cxx-benchmarks ${LIBCXX_TEST_DEPS}
+          DEPENDS cxx-benchmarks cxx-test-depends
           ARGS ${BENCHMARK_LIT_ARGS})
 endif()

libcxx/modules/CMakeLists.txt

@@ -202,6 +202,7 @@ add_custom_target(generate-cxx-modules
   ALL DEPENDS
     ${_all_modules}
 )
+add_dependencies(cxx-test-depends generate-cxx-modules)
 
 # Configure the modules manifest.
 # Use the relative path between the installation and the module in the json

libcxx/src/CMakeLists.txt

@@ -322,6 +322,7 @@ endif()
 
 # Add a meta-target for both libraries.
 add_custom_target(cxx DEPENDS ${LIBCXX_BUILD_TARGETS})
+add_dependencies(cxx-test-depends cxx)
 
 set(LIBCXX_EXPERIMENTAL_SOURCES
   experimental/keep.cpp
@@ -366,6 +367,7 @@ set_target_properties(cxx_experimental
 )
 cxx_add_common_build_flags(cxx_experimental)
 target_compile_options(cxx_experimental PUBLIC -D_LIBCPP_ENABLE_EXPERIMENTAL)
+add_dependencies(cxx-test-depends cxx_experimental)
 
 if (LIBCXX_INSTALL_SHARED_LIBRARY)
   install(TARGETS cxx_shared

libcxx/test/CMakeLists.txt

@@ -1,11 +1,5 @@
 include(HandleLitArguments)
 add_subdirectory(tools)
-# When the tools add clang-tidy support, the dependencies need to be updated.
-# This cannot be done in the tools CMakeLists.txt since that does not update
-# the status in this (a parent) directory.
-if(TARGET cxx-tidy)
-  list(APPEND LIBCXX_TEST_DEPS cxx-tidy)
-endif()
 
 # By default, libcxx and libcxxabi share a library directory.
 if (NOT LIBCXX_CXX_ABI_LIBRARY_PATH)
@@ -40,10 +34,6 @@ endif()
 
 serialize_lit_params_list(SERIALIZED_LIT_PARAMS LIBCXX_TEST_PARAMS)
 
-if (NOT DEFINED LIBCXX_TEST_DEPS)
-  message(FATAL_ERROR "Expected LIBCXX_TEST_DEPS to be defined")
-endif()
-
 if (MSVC)
   # Shared code for initializing some parameters used by all
   # llvm-libc++-*-clangcl.cfg.in test configs.
@@ -81,10 +71,6 @@ if (LIBCXX_INCLUDE_TESTS)
     ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
     MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py")
 
-  add_custom_target(cxx-test-depends
-    DEPENDS cxx ${LIBCXX_TEST_DEPS}
-    COMMENT "Builds dependencies required to run the test suite.")
-
   add_lit_testsuite(check-cxx
     "Running libcxx tests"
     ${CMAKE_CURRENT_BINARY_DIR}

libcxx/test/tools/clang_tidy_checks/CMakeLists.txt

@@ -110,3 +110,5 @@ set_target_properties(cxx-tidy PROPERTIES
 
 set_target_properties(cxx-tidy PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 set(CMAKE_SHARED_MODULE_SUFFIX_CXX .plugin) # Use a portable suffix to simplify how we can find it from Lit
+
+add_dependencies(cxx-test-depends cxx-tidy)

libcxxabi/CMakeLists.txt

@@ -443,6 +443,9 @@ if (NOT "${LIBCXXABI_LIBUNWIND_INCLUDES_INTERNAL}" STREQUAL "")
   include_directories("${LIBCXXABI_LIBUNWIND_INCLUDES_INTERNAL}")
 endif()
 
+add_custom_target(cxxabi-test-depends
+  COMMENT "Build dependencies required to run the libc++abi test suite.")
+
 # Add source code. This also contains all of the logic for deciding linker flags
 # soname, etc...
 add_subdirectory(include)

libcxxabi/src/CMakeLists.txt

@@ -304,6 +304,7 @@ endif()
 
 # Add a meta-target for both libraries.
 add_custom_target(cxxabi DEPENDS ${LIBCXXABI_BUILD_TARGETS})
+add_dependencies(cxxabi-test-depends cxxabi cxx)
 
 if (LIBCXXABI_INSTALL_LIBRARY)
   install(TARGETS ${LIBCXXABI_INSTALL_TARGETS}

libcxxabi/test/CMakeLists.txt

@@ -10,17 +10,6 @@ endmacro()
 
 pythonize_bool(LIBCXXABI_USE_LLVM_UNWINDER)
 
-if (LIBCXXABI_ENABLE_SHARED)
-  set(LIBCXXABI_TEST_DEPS cxxabi_shared)
-else()
-  set(LIBCXXABI_TEST_DEPS cxxabi_static)
-endif()
-
-list(APPEND LIBCXXABI_TEST_DEPS cxx)
-if (LIBCXXABI_USE_LLVM_UNWINDER AND TARGET unwind)
-  list(APPEND LIBCXXABI_TEST_DEPS unwind)
-endif()
-
 set(AUTO_GEN_COMMENT "## Autogenerated by libcxxabi configuration.\n# Do not edit!")
 set(SERIALIZED_LIT_PARAMS "# Lit parameters serialized here for llvm-lit to pick them up\n")
 
@@ -59,4 +48,4 @@ configure_lit_site_cfg(
 
 add_lit_testsuite(check-cxxabi "Running libcxxabi tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ${LIBCXXABI_TEST_DEPS})
+  DEPENDS cxxabi-test-depends)

libunwind/test/CMakeLists.txt

@@ -47,4 +47,4 @@ configure_lit_site_cfg(
 
 add_lit_testsuite(check-unwind "Running libunwind tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS unwind ${LIBUNWIND_TEST_DEPS})
+  DEPENDS unwind)