[openmp] Create a local llvm-lit script when building openmp standalone

[mstorsjo]

Summary

Check whether the main llvm directory exists adjacent to the
openmp directory (when building from the monorepo, this is always
the case; if building from a separate tarball it won't be found).

If found, include the AddLLVM cmake module, which contains
functions such as add_lit_testsuite.

Use add_lit_testsuite instead of add_custom_target, and
configure_lit_site_cfg instead of the plain configure_file,
if available.

By using configure_lit_site_cfg, it includes lit.site.cfg in the
generated llvm-lit script, which allows pointing llvm-lit directly
at individual tests, instead of needing to point it at the generated
test directory in the build directory (where one can't easily run
individual tests).

This allows investigating and rerunning individual tests without
needing to run the full testsuite via "check-openmp".

This is similar to what other runtime subprojects such as libcxx
did (before libcxx entirely removed support for building standalone).
If openmp is built via the main llvm-project/runtimes directory,
that directory provides the llvm-lit script.

If building outside of the main llvm build, it's still necessary
to provide the FileCheck and "not" executables for running the
tests though.

[Meinersbur]

Why not using env LIT_FILTER=<testname> ninja check-openmp environment variable to run individual tests?

[mstorsjo]

In D137774#3935073, @Meinersbur wrote:

Why not using env LIT_FILTER=<testname> ninja check-openmp environment variable to run individual tests?

Oh, I wasn't aware of that - I guess that works in many cases too. However despite that, I think moving towards using configure_lit_site_cfg would be in line with how all other subprojects do it.

This patch is in itself also a preparatory step for being able to run tests when openmp is built via the llvm-project/runtimes directory (e.g. libcxx no longer allows being built entirely standalone).

[mstorsjo]

In D137774#3935078, @mstorsjo wrote:

In D137774#3935073, @Meinersbur wrote:

Why not using env LIT_FILTER=<testname> ninja check-openmp environment variable to run individual tests?

Oh, I wasn't aware of that - I guess that works in many cases too.

... but I guess that syntax doesn't work when running things from cmd.exe?

[mstorsjo]

In D137774#3935079, @mstorsjo wrote:

In D137774#3935078, @mstorsjo wrote:

In D137774#3935073, @Meinersbur wrote:

Why not using env LIT_FILTER=<testname> ninja check-openmp environment variable to run individual tests?

Oh, I wasn't aware of that - I guess that works in many cases too.

... but I guess that syntax doesn't work when running things from cmd.exe?

Also - by calling lit directly, it's easy to request it to e.g. run specific subsets of the tests, by listing one or more directories.

openmp/CMakeLists.txt

if (OPENMP_STANDALONE_BUILD)
   set(OPENMP_INSTALL_LIBDIR "lib${OPENMP_LIBDIR_SUFFIX}")
 
   # Group test settings.
   set(OPENMP_TEST_C_COMPILER ${CMAKE_C_COMPILER} CACHE STRING
     "C compiler to use for testing OpenMP runtime libraries.")
   set(OPENMP_TEST_CXX_COMPILER ${CMAKE_CXX_COMPILER} CACHE STRING
     "C++ compiler to use for testing OpenMP runtime libraries.")
   set(OPENMP_LLVM_TOOLS_DIR "" CACHE PATH "Path to LLVM tools for testing.")
+
+  if (NOT DEFINED LLVM_PATH)
+    set(LLVM_PATH ${CMAKE_CURRENT_LIST_DIR}/../llvm CACHE PATH "" FORCE)
+  endif()
+
+  if(NOT IS_DIRECTORY ${LLVM_PATH})
+    message(WARNING
+      "The provided LLVM_PATH (${LLVM_PATH}) is not a valid directory.")
+  endif()
+
+  set(LLVM_PATH ${LLVM_PATH} CACHE PATH "Path to LLVM source tree")
+  set(LLVM_MAIN_SRC_DIR ${LLVM_PATH})
+  set(LLVM_CMAKE_DIR "${LLVM_PATH}/cmake/modules")
+
+  set(LLVM_LIT_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/bin")
+
+  if (EXISTS "${LLVM_CMAKE_DIR}")
+    list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
+    find_package(Python3 REQUIRED COMPONENTS Interpreter)
+    include(AddLLVM)
+  endif()
+
+  set(DEFAULT_LIT_ARGS "-sv --show-unsupported --show-xfail")
+  if (MSVC OR XCODE)
+    set(DEFAULT_LIT_ARGS "${DEFAULT_LIT_ARGS} --no-progress-bar")
+  endif()
+  set(OPENMP_LIT_ARGS "${DEFAULT_LIT_ARGS}" CACHE STRING "Options for lit.")
+  set(LLVM_LIT_ARGS "${OPENMP_LIT_ARGS}")
+  separate_arguments(OPENMP_LIT_ARGS)
 else()
   set(OPENMP_ENABLE_WERROR ${LLVM_ENABLE_WERROR})
   # If building in tree, we honor the same install suffix LLVM uses.
   set(OPENMP_INSTALL_LIBDIR "lib${LLVM_LIBDIR_SUFFIX}")
 
   if (NOT MSVC)
     set(OPENMP_TEST_C_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
     set(OPENMP_TEST_CXX_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++)

 
 option(OPENMP_MSVC_NAME_SCHEME "Build dll with MSVC naming scheme." OFF)
 
 # Build documentation
 add_subdirectory(docs)
 
 # Now that we have seen all testsuites, create the check-openmp target.
 construct_check_openmp_target()
+
+if (OPENMP_STANDALONE_BUILD AND EXISTS "${LLVM_MAIN_SRC_DIR}")
+  # Make sure the llvm-lit script is generated into the bin directory, and
+  # do it after adding all tests, since the generated script will only work
+  # correctly discovered tests against test locations from the source tree
+  # that have already been discovered.
+  add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/llvm-lit
+                   ${CMAKE_CURRENT_BINARY_DIR}/llvm-lit)
+endif()

openmp/cmake/OpenMPTesting.cmake

 # Keep track if we have all dependencies.
 set(ENABLE_CHECK_TARGETS TRUE)
 
 # Function to find required dependencies for testing.
 function(find_standalone_test_dependencies)
   include(FindPythonInterp)
 
   if (NOT PYTHONINTERP_FOUND)
     message(STATUS "Could not find Python.")
     message(WARNING "The check targets will not be available!")
     set(ENABLE_CHECK_TARGETS FALSE PARENT_SCOPE)
     return()
   endif()
 
   # Find executables.
+  # If we've got add_lit_testsuite, we've got the main llvm source directory,
+  # and will generate the llvm-lit script at the end.
+  if (NOT COMMAND add_lit_testsuite)
     find_program(OPENMP_LLVM_LIT_EXECUTABLE
       NAMES llvm-lit.py llvm-lit lit.py lit
       PATHS ${OPENMP_LLVM_TOOLS_DIR})
     if (NOT OPENMP_LLVM_LIT_EXECUTABLE)
       message(STATUS "Cannot find llvm-lit.")
       message(STATUS "Please put llvm-lit in your PATH, set OPENMP_LLVM_LIT_EXECUTABLE to its full path, or point OPENMP_LLVM_TOOLS_DIR to its directory.")
       message(WARNING "The check targets will not be available!")
       set(ENABLE_CHECK_TARGETS FALSE PARENT_SCOPE)
       return()
     endif()
+  endif()
 
   find_program(OPENMP_FILECHECK_EXECUTABLE
     NAMES FileCheck
     PATHS ${OPENMP_LLVM_TOOLS_DIR})
   if (NOT OPENMP_FILECHECK_EXECUTABLE)
     message(STATUS "Cannot find FileCheck.")
     message(STATUS "Please put FileCheck in your PATH, set OPENMP_FILECHECK_EXECUTABLE to its full path, or point OPENMP_LLVM_TOOLS_DIR to its directory.")
     message(WARNING "The check targets will not be available!")
if (NOT OPENMP_NOT_EXECUTABLE)
     message(WARNING "The check targets will not be available!")
     set(ENABLE_CHECK_TARGETS FALSE PARENT_SCOPE)
     return()
   endif()
 endfunction()
 
 if (${OPENMP_STANDALONE_BUILD})
   find_standalone_test_dependencies()
-
-  # Set lit arguments.
-  set(DEFAULT_LIT_ARGS "-sv --show-unsupported --show-xfail")
-  if (MSVC OR XCODE)
-    set(DEFAULT_LIT_ARGS "${DEFAULT_LIT_ARGS} --no-progress-bar")
-  endif()
-  set(OPENMP_LIT_ARGS "${DEFAULT_LIT_ARGS}" CACHE STRING "Options for lit.")
-  separate_arguments(OPENMP_LIT_ARGS)
 else()
   if (NOT TARGET "FileCheck")
     message(STATUS "Cannot find 'FileCheck'.")
     message(WARNING "The check targets will not be available!")
     set(ENABLE_CHECK_TARGETS FALSE)
   else()
     set(OPENMP_FILECHECK_EXECUTABLE ${LLVM_RUNTIME_OUTPUT_INTDIR}/FileCheck)
   endif()
function(add_openmp_testsuite target comment)
   cmake_parse_arguments(ARG "EXCLUDE_FROM_CHECK_ALL" "" "DEPENDS;ARGS" ${ARGN})
   # EXCLUDE_FROM_CHECK_ALL excludes the test ${target} out of check-openmp.
   if (NOT ARG_EXCLUDE_FROM_CHECK_ALL)
     # Register the testsuites and depends for the check-openmp rule.
     set_property(GLOBAL APPEND PROPERTY OPENMP_LIT_TESTSUITES ${ARG_UNPARSED_ARGUMENTS})
     set_property(GLOBAL APPEND PROPERTY OPENMP_LIT_DEPENDS ${ARG_DEPENDS})
   endif()
 
-  if (${OPENMP_STANDALONE_BUILD})
+  if (NOT COMMAND add_lit_testsuite)
     set(LIT_ARGS ${OPENMP_LIT_ARGS} ${ARG_ARGS})
     add_custom_target(${target}
       COMMAND ${PYTHON_EXECUTABLE} ${OPENMP_LLVM_LIT_EXECUTABLE} ${LIT_ARGS} ${ARG_UNPARSED_ARGUMENTS}
       COMMENT ${comment}
       DEPENDS ${ARG_DEPENDS}
       USES_TERMINAL
     )
   else()
+    if (NOT OPENMP_STANDALONE_BUILD)
+      list(APPEND ARG_DEPENDS clang FileCheck not)
+    endif()
+
     if (ARG_EXCLUDE_FROM_CHECK_ALL)
       add_lit_testsuite(${target}
         ${comment}
         ${ARG_UNPARSED_ARGUMENTS}
         EXCLUDE_FROM_CHECK_ALL
-        DEPENDS clang FileCheck not ${ARG_DEPENDS}
+        DEPENDS ${ARG_DEPENDS}
         ARGS ${ARG_ARGS}
       )
     else()
       add_lit_testsuite(${target}
         ${comment}
         ${ARG_UNPARSED_ARGUMENTS}
-        DEPENDS clang FileCheck not ${ARG_DEPENDS}
+        DEPENDS ${ARG_DEPENDS}
         ARGS ${ARG_ARGS}
       )
     endif()
   endif()
 endfunction()
 
 function(construct_check_openmp_target)
   get_property(OPENMP_LIT_TESTSUITES GLOBAL PROPERTY OPENMP_LIT_TESTSUITES)
   get_property(OPENMP_LIT_DEPENDS GLOBAL PROPERTY OPENMP_LIT_DEPENDS)
 
   # We already added the testsuites themselves, no need to do that again.
   add_openmp_testsuite(check-openmp "Running OpenMP tests" ${OPENMP_LIT_TESTSUITES} EXCLUDE_FROM_CHECK_ALL DEPENDS ${OPENMP_LIT_DEPENDS})
 endfunction()

openmp/runtime/test/CMakeLists.txt

 
 
 add_openmp_testsuite(check-libomp "Running libomp tests" ${CMAKE_CURRENT_BINARY_DIR} DEPENDS omp)
 # Add target check-ompt, but make sure to not add the tests twice to check-openmp.
 add_openmp_testsuite(check-ompt "Running OMPT tests" ${CMAKE_CURRENT_BINARY_DIR}/ompt EXCLUDE_FROM_CHECK_ALL DEPENDS omp)
 
 # Configure the lit.site.cfg.in file
 set(AUTO_GEN_COMMENT "## Autogenerated by libomp configuration.\n# Do not edit!")
+if (COMMAND configure_lit_site_cfg)
+  configure_lit_site_cfg("${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in" "${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg"
+      MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg")
+else()
+  # Building standalone, without the main llvm directory available.
   configure_file(lit.site.cfg.in lit.site.cfg @ONLY)
+endif()