[libcxxabi] Allow building with sanitizers enabled

[ldionne]

Summary

I copied the sanitizer-related logic in libcxx/lib/CMakeLists.txt. In
the future, it would be great to avoid duplicating this logic in the
compiler, libc++ and libc++abi.

[mclow.lists]

Other than above, this looks fine to me - but I haven't done much to the CMake stuff. Waiting for @EricWF to take a look.

libcxxabi/src/CMakeLists.txt

116

Is this just a Mac OS X feature, then?

[EricWF]

@ldionne This looks fine to me, but I don't love the duplication.

I think this patch gives yet another reason why libc++ and libc++abi should live in the same repo.

libcxxabi/src/CMakeLists.txt

116

We only need this configuration on Mac OS X because the Clang driver on other platforms links these libraries for us.

[ldionne]

libcxxabi/src/CMakeLists.txt

116

Is this not a Clang bug, then?

libcxxabi/src/CMakeLists.txt

list(APPEND LIBCXXABI_SHARED_LINK_FLAGS
       "-install_name /usr/lib/libc++abi.1.dylib")
     list(APPEND LIBCXXABI_LINK_FLAGS
         "/usr/lib/libSystem.B.dylib")
   else()
     list(APPEND LIBCXXABI_SHARED_LINK_FLAGS
       "-compatibility_version 1"
       "-install_name /usr/lib/libc++abi.1.dylib")
   endif()
+
+  if (LLVM_USE_SANITIZER)
+    if (("${LLVM_USE_SANITIZER}" STREQUAL "Address") OR
+        ("${LLVM_USE_SANITIZER}" STREQUAL "Address;Undefined") OR
+        ("${LLVM_USE_SANITIZER}" STREQUAL "Undefined;Address"))
+      set(LIBFILE "libclang_rt.asan_osx_dynamic.dylib")
+    elseif("${LLVM_USE_SANITIZER}" STREQUAL "Undefined")
+      set(LIBFILE "libclang_rt.ubsan_osx_dynamic.dylib")
+    elseif("${LLVM_USE_SANITIZER}" STREQUAL "Thread")
+      set(LIBFILE "libclang_rt.tsan_osx_dynamic.dylib")
+    else()
+      message(WARNING "LLVM_USE_SANITIZER=${LLVM_USE_SANITIZER} is not supported on OS X")
+    endif()
+    if (LIBFILE)
+      find_compiler_rt_dir(LIBDIR)
+      if (NOT IS_DIRECTORY "${LIBDIR}")
+        message(FATAL_ERROR "Cannot find compiler-rt directory on OS X required for LLVM_USE_SANITIZER")
+      endif()
+      set(LIBCXXABI_SANITIZER_LIBRARY "${LIBDIR}/${LIBFILE}")
+      set(LIBCXXABI_SANITIZER_LIBRARY "${LIBCXXABI_SANITIZER_LIBRARY}" PARENT_SCOPE)
+      message(STATUS "Manually linking compiler-rt library: ${LIBCXXABI_SANITIZER_LIBRARY}")
+      add_library_flags("${LIBCXXABI_SANITIZER_LIBRARY}")
+      add_link_flags("-Wl,-rpath,${LIBDIR}")
+    endif()
+  endif()
 endif()
 
 split_list(LIBCXXABI_COMPILE_FLAGS)
 split_list(LIBCXXABI_LINK_FLAGS)
 split_list(LIBCXXABI_SHARED_LINK_FLAGS)
 
 # FIXME: libc++abi.so will not link when modules are enabled because it depends
 # on symbols defined in libc++.so which has not yet been built.

libcxxabi/test/lit.site.cfg.in

 @AUTO_GEN_COMMENT@
 config.cxx_under_test           = "@LIBCXXABI_COMPILER@"
 config.project_obj_root         = "@CMAKE_BINARY_DIR@"
 config.libcxxabi_src_root       = "@LIBCXXABI_SOURCE_DIR@"
 config.libcxxabi_obj_root       = "@LIBCXXABI_BINARY_DIR@"
 config.abi_library_path         = "@LIBCXXABI_LIBRARY_DIR@"
 config.libcxx_src_root          = "@LIBCXXABI_LIBCXX_PATH@"
 config.cxx_headers              = "@LIBCXXABI_LIBCXX_INCLUDES@"
 config.libunwind_headers        = "@LIBCXXABI_LIBUNWIND_INCLUDES_INTERNAL@"
 config.cxx_library_root         = "@LIBCXXABI_LIBCXX_LIBRARY_PATH@"
 config.llvm_unwinder            = "@LIBCXXABI_USE_LLVM_UNWINDER@"
 config.enable_threads           = "@LIBCXXABI_ENABLE_THREADS@"
 config.use_sanitizer            = "@LLVM_USE_SANITIZER@"
+config.sanitizer_library        = "@LIBCXXABI_SANITIZER_LIBRARY@"
 config.enable_32bit             = "@LIBCXXABI_BUILD_32_BITS@"
 config.target_info              = "@LIBCXXABI_TARGET_INFO@"
 config.executor                 = "@LIBCXXABI_EXECUTOR@"
 config.libcxxabi_shared         = "@LIBCXXABI_ENABLE_SHARED@"
 config.enable_shared            = "@LIBCXX_ENABLE_SHARED@"
 config.enable_exceptions        = "@LIBCXXABI_ENABLE_EXCEPTIONS@"
 config.host_triple              = "@LLVM_HOST_TRIPLE@"
 config.target_triple            = "@TARGET_TRIPLE@"
 config.use_target               = len("@LIBCXXABI_TARGET_TRIPLE@") > 0
 config.sysroot                  = "@LIBCXXABI_SYSROOT@"
 config.gcc_toolchain            = "@LIBCXXABI_GCC_TOOLCHAIN@"
 config.cxx_ext_threads          = "@LIBCXXABI_BUILD_EXTERNAL_THREAD_LIBRARY@"
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LIBCXXABI_SOURCE_DIR@/test/lit.cfg")