[openmp] [test] XFAIL many-microtask-args.c on ARM

[mstorsjo]

Summary

On ARM, a C fallback version of __kmp_invoke_microtask is used,
which only handles up to a fixed number of arguments - while
many-microtask-args.c tests that the function can handle an
arbitrarily large number of arguments (the testcase produces 17
arguments).

On the CMake level, we can't add ${LIBOMP_ARCH} directly to
OPENMP_TEST_COMPILER_FEATURES in OpenMPTesting.cmake, since
that file is parsed before LIBOMP_ARCH is set. Instead
convert the feature list into a proper CMake list, and append
${LIBOMP_ARCH} into it before serializing it to an Python array.

[protze.joachim]

LGTM

[natgla]

openmp/runtime/test/misc_bugs/many-microtask-args.c

7

Does this test now always expect a failure on arm? E.g. with MSVC on Windows it should pass, but it'll expect failure, so if there will be a breaking change test may start failing with MSVC and it'll go unnoticed, correct?

[natgla]

openmp/runtime/test/misc_bugs/many-microtask-args.c

7

or is this for arm 32, not aarch64?

[mstorsjo]

openmp/runtime/test/misc_bugs/many-microtask-args.c

7

This is only for 32 bit arm, arm64 gets LIBOMP_ARCH=aarch64.

[mstorsjo]

Make sure OPENMP_TEST_COMPILER_FEATURES is defined properly in all other test subdirectories other than runtime/test.

Also remove accidental commas from the end of entries in OPENMP_TEST_COMPILER_FEATURE_LIST.

openmp/cmake/OpenMPTesting.cmake

function(set_test_compiler_features)
   if ("${OPENMP_TEST_COMPILER_ID}" STREQUAL "GNU")
     set(comp "gcc")
   elseif ("${OPENMP_TEST_COMPILER_ID}" STREQUAL "Intel")
     set(comp "icc")
   else()
     # Just use the lowercase of the compiler ID as fallback.
     string(TOLOWER "${OPENMP_TEST_COMPILER_ID}" comp)
   endif()
-  set(OPENMP_TEST_COMPILER_FEATURES "['${comp}', '${comp}-${OPENMP_TEST_COMPILER_VERSION_MAJOR}', '${comp}-${OPENMP_TEST_COMPILER_VERSION_MAJOR_MINOR}', '${comp}-${OPENMP_TEST_COMPILER_VERSION}']" PARENT_SCOPE)
+  set(OPENMP_TEST_COMPILER_FEATURE_LIST ${comp}, ${comp}-${OPENMP_TEST_COMPILER_VERSION_MAJOR}, ${comp}-${OPENMP_TEST_COMPILER_VERSION_MAJOR_MINOR}, ${comp}-${OPENMP_TEST_COMPILER_VERSION} PARENT_SCOPE)
 endfunction()
 set_test_compiler_features()
 
 # Function to add a testsuite for an OpenMP runtime library.
 function(add_openmp_testsuite target comment)
   if (NOT ENABLE_CHECK_TARGETS)
     add_custom_target(${target}
       COMMAND ${CMAKE_COMMAND} -E echo "${target} does nothing, dependencies not found.")

openmp/runtime/test/CMakeLists.txt

 macro(pythonize_bool var)
   if (${var})
     set(${var} True)
   else()
     set(${var} False)
   endif()
 endmacro()
 
+list(APPEND OPENMP_TEST_COMPILER_FEATURE_LIST "${LIBOMP_ARCH}")
+set(OPENMP_TEST_COMPILER_FEATURES "[")
+set(first TRUE)
+foreach(feat IN LISTS OPENMP_TEST_COMPILER_FEATURE_LIST)
+  if (NOT first)
+    string(APPEND OPENMP_TEST_COMPILER_FEATURES ", ")
+  endif()
+  set(first FALSE)
+  string(APPEND OPENMP_TEST_COMPILER_FEATURES "'${feat}'")
+endforeach()
+string(APPEND OPENMP_TEST_COMPILER_FEATURES "]")
+
 pythonize_bool(LIBOMP_USE_HWLOC)
 pythonize_bool(LIBOMP_OMPT_SUPPORT)
 pythonize_bool(LIBOMP_OMPT_OPTIONAL)
 pythonize_bool(LIBOMP_HAVE_LIBM)
 pythonize_bool(LIBOMP_HAVE_LIBATOMIC)
 pythonize_bool(OPENMP_STANDALONE_BUILD)
 pythonize_bool(OPENMP_TEST_COMPILER_HAS_OMIT_FRAME_POINTER_FLAGS)
 pythonize_bool(OPENMP_TEST_COMPILER_HAS_OMP_H)

openmp/runtime/test/misc_bugs/many-microtask-args.c

 // RUN: %libomp-compile-and-run
 #include <stdio.h>
 
+// This test fails with Clang unless __kmp_invoke_microtask supports at least
+// 17 arguments. On ARM, the fallback C implementation of __kmp_invoke_microtask
+// is used, and that one only currently supports up to 15 arguments.
+// XFAIL: arm
+
 int main()
 {
 
   int i;
   int i1 = 0;
   int i2 = 1;
   int i3 = 2;
   int i4 = 3;