[openmp] Fix enumeration build issue for openmp library

[ronlieb]

Summary

integer value 40962 is outside the valid range of values [0, 31] for this enumeration type [-Wenum-constexpr-conversion]` (Issue #57022)

turn on -Wno-enum-constexpr-conversion to buy some time to fix the more egregious issue in hsa_agent_into_t and hsa_amd_agent_info_t interfaces.

relates to https://reviews.llvm.org/D131307/new/

[JonChesterfield]

Sure. Have you tagged Sean on this to workaround in the lib? I don't see how an enum without specified type could be smaller than int, so that's either an edge in C++ I didn't notice or too aggressive behaviour from clang

[JonChesterfield]

Ah. So C++ have decided writing a value outside the range of initial values is UB. C still thinks it's an int afaik. So that's a somewhat gratuitous break for shared headers. https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#2338

Whatever, workaround is trivial. The enum needs to gain a field _unused_work_around_D2338 = INT32_MAX

[sylvestre.ledru]

thanks!

[shafik]

In my new PR: https://reviews.llvm.org/D150226 in which I am planning on turning off the ability to turn the error into a warning this change was flagged.

According to one of the comments the workaround to this is trivial, can we remediate the issue so we can help unblock the PR.

openmp/cmake/HandleOpenMPOptions.cmake

 
 # Additional warnings that are not enabled by -Wall.
 append_if(OPENMP_HAVE_WCAST_QUAL_FLAG "-Wcast-qual" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WFORMAT_PEDANTIC_FLAG "-Wformat-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WIMPLICIT_FALLTHROUGH_FLAG "-Wimplicit-fallthrough" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WSIGN_COMPARE_FLAG "-Wsign-compare" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 
 # Warnings that we want to disable because they are too verbose or fragile.
+append_if(OPENMP_HAVE_WNO_ENUM_CONSTEXPR_CONVERSION_FLAG "-Wno-enum-constexpr-conversion" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WNO_EXTRA_FLAG "-Wno-extra" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WNO_PEDANTIC_FLAG "-Wno-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 append_if(OPENMP_HAVE_WNO_MAYBE_UNINITIALIZED_FLAG "-Wno-maybe-uninitialized" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 
 append_if(OPENMP_HAVE_STD_CPP17_FLAG "-std=c++17" CMAKE_CXX_FLAGS)

openmp/cmake/config-ix.cmake

 
 # Additional warnings that are not enabled by -Wall.
 check_cxx_compiler_flag(-Wcast-qual OPENMP_HAVE_WCAST_QUAL_FLAG)
 check_cxx_compiler_flag(-Wformat-pedantic OPENMP_HAVE_WFORMAT_PEDANTIC_FLAG)
 check_cxx_compiler_flag(-Wimplicit-fallthrough OPENMP_HAVE_WIMPLICIT_FALLTHROUGH_FLAG)
 check_cxx_compiler_flag(-Wsign-compare OPENMP_HAVE_WSIGN_COMPARE_FLAG)
 
 # Warnings that we want to disable because they are too verbose or fragile.
+check_cxx_compiler_flag(-Wno-enum-constexpr-conversion OPENMP_HAVE_WNO_ENUM_CONSTEXPR_CONVERSION_FLAG)
 check_cxx_compiler_flag(-Wno-extra OPENMP_HAVE_WNO_EXTRA_FLAG)
 check_cxx_compiler_flag(-Wno-pedantic OPENMP_HAVE_WNO_PEDANTIC_FLAG)
 check_cxx_compiler_flag(-Wno-maybe-uninitialized OPENMP_HAVE_WNO_MAYBE_UNINITIALIZED_FLAG)
 
 check_cxx_compiler_flag(-std=c++17 OPENMP_HAVE_STD_CPP17_FLAG)