libc++abi: work around layering violation

This papers over a layering violation currently between libc++abi and libunwind.
It reaches into the sources to get the declaration of an ABI defined function.
This should allow the ARM buildbot to continue building libc++abi again.

llvm-svn: 235965

libcxxabi/CMakeLists.txt

@@ -302,6 +302,10 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${LIBCXXABI_C_FLAGS}")
 include_directories(include)
 if (LIBCXXABI_USE_LLVM_UNWINDER OR ${LLVM_NATIVE_ARCH} MATCHES ARM)
   include_directories(${LLVM_MAIN_SRC_DIR}/projects/libunwind/include)
+  # TODO: libunwind does not place libunwind_ext.h into include, so we need to
+  # reach into its source directory.  This is primarily for
+  # _Unwind_VRS_Interpret, which is part of ARM EHABI, and should be in unwind.h
+  include_directories(${LLVM_MAIN_SRC_DIR}/projects/libunwind/src)
 endif ()
 
 # Add source code. This also contains all of the logic for deciding linker flags

libcxxabi/src/cxa_personality.cpp

@@ -24,7 +24,7 @@
 #include "unwind.h"
 
 #if LIBCXXABI_ARM_EHABI
-#include "Unwind/libunwind_ext.h"
+#include "libunwind_ext.h"
 #endif
 
 /*