From dbcd7a35f8e88c68f454107f4dbd45aa6b4377a2 Mon Sep 17 00:00:00 2001
From: Logan Chien <tzuhsiang.chien@gmail.com>
Date: Thu, 22 Jan 2015 13:39:08 +0000
Subject: [PATCH] Add -funwind-tables to CMAKE_C_FLAGS.

Without -funwind-tables, the compiler won't generate the unwinding
table for these C functions.  However, the functions in libunwind,
such as `_Unwind_Backtrace()`, WILL unwind stack to get the backtrace.

llvm-svn: 226823
---
 libcxxabi/CMakeLists.txt        | 4 ++++
 libcxxabi/cmake/config-ix.cmake | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
index aaada04..6be1e15 100644
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -164,6 +164,7 @@ macro(append_if list condition var)
   endif()
 endmacro()
 
+set(LIBCXXABI_C_FLAGS "")
 set(LIBCXXABI_CXX_FLAGS "")
 set(LIBCXXABI_COMPILE_FLAGS "")
 set(LIBCXXABI_LINK_FLAGS "")
@@ -216,6 +217,8 @@ endif()
 append_if(LIBCXXABI_CXX_FLAGS LIBCXXABI_HAS_FSTRICT_ALIASING_FLAG -fstrict-aliasing)
 append_if(LIBCXXABI_CXX_FLAGS LIBCXXABI_HAS_EHSC_FLAG -EHsc)
 
+append_if(LIBCXXABI_C_FLAGS LIBCXXABI_HAS_FUNWIND_TABLES -funwind-tables)
+
 # Assert
 string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
 if (LIBCXXABI_ENABLE_ASSERTIONS)
@@ -260,6 +263,7 @@ append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_SYSROOT
           "--sysroot ${LIBCXXABI_SYSROOT}")
 string(REPLACE ";" " " LIBCXXABI_CXX_FLAGS "${LIBCXXABI_CXX_FLAGS}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LIBCXXABI_CXX_FLAGS}")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${LIBCXXABI_C_FLAGS}")
 
 #===============================================================================
 # Setup Source Code
diff --git a/libcxxabi/cmake/config-ix.cmake b/libcxxabi/cmake/config-ix.cmake
index ac31eed..b6ee40f 100644
--- a/libcxxabi/cmake/config-ix.cmake
+++ b/libcxxabi/cmake/config-ix.cmake
@@ -1,7 +1,9 @@
 include(CheckLibraryExists)
+include(CheckCCompilerFlag)
 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(-fstrict-aliasing     LIBCXXABI_HAS_FSTRICT_ALIASING_FLAG)
 check_cxx_compiler_flag(-nodefaultlibs        LIBCXXABI_HAS_NODEFAULTLIBS_FLAG)
-- 
2.7.4