ClickHouse/cmake/cxx.cmake

26 lines
1.4 KiB
CMake

if (CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG")
# Enable libcxx debug mode: https://releases.llvm.org/15.0.0/projects/libcxx/docs/DesignDocs/DebugMode.html
# The docs say the debug mode violates complexity guarantees, so do this only for Debug builds.
# set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -D_LIBCPP_ENABLE_DEBUG_MODE=1")
# ^^ Crashes the database upon startup, needs investigation.
# Besides that, the implementation looks like a poor man's MSAN specific to libcxx. Since CI tests MSAN
# anyways, we can keep the debug mode disabled.
# Libcxx also provides extra assertions:
# --> https://releases.llvm.org/15.0.0/projects/libcxx/docs/UsingLibcxx.html#assertions-mode
# These look orthogonal to the debug mode but the debug mode enables them implicitly:
# --> https://github.com/llvm/llvm-project/blob/release/15.x/libcxx/include/__assert#L29
# They are cheap and straightforward, so enable them in debug builds:
set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -D_LIBCPP_ENABLE_ASSERTIONS=1")
# TODO Once we upgrade to LLVM 18+, reconsider all of the above as they introduced "hardening modes":
# https://libcxx.llvm.org/Hardening.html
endif ()
add_subdirectory(contrib/libcxxabi-cmake)
add_subdirectory(contrib/libcxx-cmake)
# Exception handling library is embedded into libcxxabi.
target_link_libraries(global-libs INTERFACE cxx cxxabi)