libc++abi: enable LLVM unwinder by default for ARM

libc++abi uses EHABI extensions, which are only part of the LLVM unwinder.  When
targeting ARM by default, enable the use of the LLVM unwinder.  Hopefully this
will fix the ARM native bot

llvm-svn: 235904

diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
index 121b468..cab24b7 100644 (file)
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -114,7 +114,12 @@ endif()
 option(LIBCXXABI_ENABLE_ASSERTIONS "Enable assertions independent of build mode." ON)
 option(LIBCXXABI_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
 option(LIBCXXABI_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
-option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder." OFF)
+set(LIBCXXABI_USE_LLVM_UNWINDER_DEFAULT OFF)
+if (${LLVM_NATIVE_ARCH} MATCHES arm)
+  set(LIBCXXABI_USE_LLVM_UNWINDER_DEFAULT ON)
+endif ()
+option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder."
+       ${LIBCXXABI_USE_LLVM_UNWINDER_DEFAULT})
 option(LIBCXXABI_ENABLE_THREADS "Build with threads enabled" ON)
 set(LIBCXXABI_GCC_TOOLCHAIN "" CACHE STRING "GCC toolchain for cross compiling.")
 set(LIBCXXABI_SYSROOT "" CACHE STRING "Sysroot for cross compiling.")