From 123f44a2f6c3b19cf2d0f6a233fedb6da65edebd Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Fri, 6 Feb 2015 17:47:57 +0000
Subject: [PATCH] unwind: use -fno-rtti -fno-exceptions -funwind-tables

RTTI and exceptions are not needed for the unwinder, the use of C++ there is for
very specific cases, and does not require dynamic_cast nor does it use
exceptions.  This avoids unnecessary references to type information being
emitted.

llvm-svn: 228408
---
 libcxxabi/cmake/config-ix.cmake     | 2 ++
 libcxxabi/src/Unwind/CMakeLists.txt | 8 +++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/libcxxabi/cmake/config-ix.cmake b/libcxxabi/cmake/config-ix.cmake
index 2fea2cd9bf54..5405587554b5 100644
--- a/libcxxabi/cmake/config-ix.cmake
+++ b/libcxxabi/cmake/config-ix.cmake
@@ -5,6 +5,8 @@ include(CheckCXXCompilerFlag)
 # Check compiler flags
 check_c_compiler_flag(-funwind-tables         LIBCXXABI_HAS_FUNWIND_TABLES)
 check_cxx_compiler_flag(-fPIC                 LIBCXXABI_HAS_FPIC_FLAG)
+check_cxx_compiler_flag(-fno-exceptions       LIBCXXABI_HAS_NO_EXCEPTIONS_FLAG)
+check_cxx_compiler_flag(-fno-rtti             LIBCXXABI_HAS_NO_RTTI_FLAG)
 check_cxx_compiler_flag(-fstrict-aliasing     LIBCXXABI_HAS_FSTRICT_ALIASING_FLAG)
 check_cxx_compiler_flag(-nodefaultlibs        LIBCXXABI_HAS_NODEFAULTLIBS_FLAG)
 check_cxx_compiler_flag(-nostdinc++           LIBCXXABI_HAS_NOSTDINCXX_FLAG)
diff --git a/libcxxabi/src/Unwind/CMakeLists.txt b/libcxxabi/src/Unwind/CMakeLists.txt
index 598a081ea3de..56c217d1788a 100644
--- a/libcxxabi/src/Unwind/CMakeLists.txt
+++ b/libcxxabi/src/Unwind/CMakeLists.txt
@@ -68,6 +68,11 @@ target_link_libraries(unwind ${libraries})
 append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_HAS_FPIC_FLAG -fPIC)
 append_if(LIBCXXABI_LINK_FLAGS LIBCXXABI_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
 
+set(LIBUNWIND_COMPILE_FLAGS)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBCXXABI_HAS_NO_EXCEPTIONS_FLAG -fno-exceptions)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBCXXABI_HAS_NO_RTTI_FLAG -fno-rtti)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBCXXABI_HAS_FUNWIND_TABLES -funwind-tables)
+
 set(LIBCXXABI_UNWINDER_NAME "unwind")
 
 if ( APPLE )
@@ -86,11 +91,12 @@ if ( APPLE )
 endif()
 
 string(REPLACE ";" " " LIBCXXABI_COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}")
+string(REPLACE ";" " " LIBUNWIND_COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}")
 string(REPLACE ";" " " LIBCXXABI_LINK_FLAGS "${LIBCXXABI_LINK_FLAGS}")
 
 set_target_properties(unwind
   PROPERTIES
-    COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}"
+    COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS} ${LIBUNWIND_COMPILE_FLAGS}"
     LINK_FLAGS    "${LIBCXXABI_LINK_FLAGS}"
     OUTPUT_NAME   "${LIBCXXABI_UNWINDER_NAME}"
     VERSION       "1.0"