libunwind: add new build logic

This replicates most of the build infrastructure from libc++abi ported to
libunwind.  This allows building libunwind without requiring libc++abi.


git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@235795 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 322 insertions, 61 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..f8a8cc8
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,225 @@
+#===============================================================================
+# Setup Project
+#===============================================================================
+
+cmake_minimum_required(VERSION 2.8.8)
+
+if (POLICY CMP0042)
+  cmake_policy(SET CMP0042 NEW) # Set MACOSX_RPATH=YES by default
+endif()
+
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  project(libunwind)
+
+  # Rely on llvm-config.
+  set(CONFIG_OUTPUT)
+  find_program(LLVM_CONFIG "llvm-config")
+  if (DEFINED LLVM_PATH)
+    set(LLVM_INCLUDE_DIR ${LLVM_INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_PATH ${LLVM_PATH} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_MAIN_SRC_DIR ${LLVM_PATH})
+    set(LLVM_CMAKE_PATH "${LLVM_PATH}/cmake/modules")
+  elseif (LLVM_CONFIG)
+    message(STATUS "Found LLVM_CONFIG as ${LLVM_CONFIG}")
+    set(CONFIG_COMMAND ${LLVM_CONFIG} "--includedir" "--prefix" "--src-root")
+    execute_process(COMMAND ${CONFIG_COMMAND}
+                    RESULT_VARIABLE HAD_ERROR
+                    OUTPUT_VARIABLE CONFIG_OUTPUT)
+    if (NOT HAD_ERROR)
+      string(REGEX REPLACE "[ \t]*[\r\n]+[ \t]*" ";"
+             CONFIG_OUTPUT ${CONFIG_OUTPUT})
+    else ()
+      string(REPLACE ";" " " CONFIG_COMMAND_STR "${CONFIG_COMMAND}")
+      message(STATUS "${CONFIG_COMMAND_STR}")
+      message(FATAL_ERROR "llvm-config failed with status ${HAD_ERROR}")
+    endif ()
+
+    list(GET CONFIG_OUTPUT 0 INCLUDE_DIR)
+    list(GET CONFIG_OUTPUT 1 LLVM_OBJ_ROOT)
+    list(GET CONFIG_OUTPUT 2 MAIN_SRC_DIR)
+
+    set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
+    set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/share/llvm/cmake")
+    set(LLVM_LIT_PATH "${LLVM_PATH}/utils/lit/lit.py")
+  else ()
+    message(FATAL_ERROR "llvm-config not found and LLVM_MAIN_SRC_DIR not defined. "
+                        "Reconfigure with -DLLVM_CONFIG=path/to/llvm-config "
+                        "or -DLLVM_PATH=path/to/llvm-source-root.")
+  endif ()
+
+  if (EXISTS ${LLVM_CMAKE_PATH})
+    list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")
+    include("${LLVM_CMAKE_PATH}/AddLLVM.cmake")
+    include("${LLVM_CMAKE_PATH}/HandleLLVMOptions.cmake")
+  else ()
+    message(FATAL_ERROR "Not found: ${LLVM_CMAKE_PATH}")
+  endif ()
+
+  set(PACKAGE_NAME libunwind)
+  set(PACKAGE_VERSION 3.7.0svn)
+  set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+  set(PACKAGE_BUGREPORT "llvmbugs@cs.uiuc.edu")
+
+  if (EXISTS ${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py)
+    set(LLVM_LIT ${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py)
+  else ()
+    # Seek installed Lit.
+    find_program(LLVM_LIT "lit.py" ${LLVM_MAIN_SRC_DIR}/utils/lit
+                 DOC "Path to lit.py")
+  endif ()
+
+  if (LLVM_LIT)
+    # Define the default arguments to use with 'lit', and an option for the user
+    # to override.
+    set(LIT_ARGS_DEFAULT "-sv")
+    if (MSVC OR XCODE)
+      set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
+    endif ()
+    set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
+
+    # On Win32 hosts, provide an option to specify the path to the GnuWin32 tools.
+    if (WIN32 AND NOT CYGWIN)
+      set(LLVM_LIT_TOOLS_DIR "" CACHE PATH "Path to GnuWin32 tools")
+    endif ()
+  else ()
+    set(LLVM_INCLUDE_TESTS OFF)
+  endif ()
+
+  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX})
+  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX})
+else()
+  set(LLVM_MAIN_SRC_DIR "${CMAKE_SOURCE_DIR}" CACHE PATH "Path to LLVM source tree")
+  set(LLVM_LIT "${CMAKE_SOURCE_DIR}/utils/lit/lit.py")
+endif()
+
+#===============================================================================
+# Setup CMake Options
+#===============================================================================
+
+# Define options.
+option(LIBUNWIND_ENABLE_ASSERTIONS "Enable assertions independent of build mode." ON)
+option(LIBUNWIND_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
+option(LIBUNWIND_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
+option(LIBUNWIND_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
+option(LIBUNWIND_ENABLE_SHARED "Build libunwind as a shared library." ON)
+
+set(LIBUNWIND_GCC_TOOLCHAIN "" CACHE STRING "GCC toolchain for cross compiling.")
+set(LIBUNWIND_SYSROOT "" CACHE STRING "Sysroot for cross compiling.")
+
+#===============================================================================
+# Configure System
+#===============================================================================
+
+# Add path for custom modules
+set(CMAKE_MODULE_PATH
+    "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+    ${CMAKE_MODULE_PATH})
+
+# Configure compiler.
+include(config-ix)
+
+set(LIBUNWIND_COMPILER    ${CMAKE_CXX_COMPILER})
+set(LIBUNWIND_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
+set(LIBUNWIND_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
+set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX})
+
+#===============================================================================
+# Setup Compiler Flags
+#===============================================================================
+
+# Get required flags.
+macro(append_if list condition var)
+  if (${condition})
+    list(APPEND ${list} ${var})
+  endif()
+endmacro()
+
+set(LIBUNWIND_C_FLAGS "")
+set(LIBUNWIND_CXX_FLAGS "")
+set(LIBUNWIND_COMPILE_FLAGS "")
+set(LIBUNWIND_LINK_FLAGS "")
+
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WERROR_FLAG -Werror=return-type)
+
+# Get warning flags
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_W_FLAG -W)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WALL_FLAG -Wall)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WCHAR_SUBSCRIPTS_FLAG -Wchar-subscripts)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WCONVERSION_FLAG -Wconversion)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WMISMATCHED_TAGS_FLAG -Wmismatched-tags)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WMISSING_BRACES_FLAG -Wmissing-braces)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WNEWLINE_EOF_FLAG -Wnewline-eof)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WNO_UNUSED_FUNCTION_FLAG -Wno-unused-function)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSHADOW_FLAG -Wshadow)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSHORTEN_64_TO_32_FLAG -Wshorten-64-to-32)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSIGN_COMPARE_FLAG -Wsign-compare)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSIGN_CONVERSION_FLAG -Wsign-conversion)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSTRICT_ALIASING_FLAG -Wstrict-aliasing=2)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WSTRICT_OVERFLOW_FLAG -Wstrict-overflow=4)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WUNUSED_PARAMETER_FLAG -Wunused-parameter)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WUNUSED_VARIABLE_FLAG -Wunused-variable)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WWRITE_STRINGS_FLAG -Wwrite-strings)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WUNDEF_FLAG -Wundef)
+
+if (LIBUNWIND_ENABLE_WERROR)
+  append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WERROR_FLAG -Werror)
+  append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WX_FLAG -WX)
+else()
+  append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_WNO_ERROR_FLAG -Wno-error)
+  append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_NO_WX_FLAG -WX-)
+endif()
+
+if (LIBUNWIND_ENABLE_PEDANTIC)
+  append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_PEDANTIC_FLAG -pedantic)
+endif()
+
+# Get feature flags.
+# Exceptions
+# Catches C++ exceptions only and tells the compiler to assume that extern C
+# functions never throw a C++ exception.
+append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_FSTRICT_ALIASING_FLAG -fstrict-aliasing)
+append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_EHSC_FLAG -EHsc)
+
+append_if(LIBUNWIND_C_FLAGS LIBUNWIND_HAS_FUNWIND_TABLES -funwind-tables)
+
+# Assert
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+if (LIBUNWIND_ENABLE_ASSERTIONS)
+  # MSVC doesn't like _DEBUG on release builds. See PR 4379.
+  if (NOT MSVC)
+    list(APPEND LIBUNWIND_COMPILE_FLAGS -D_DEBUG)
+  endif ()
+
+  # On Release builds cmake automatically defines NDEBUG, so we
+  # explicitly undefine it:
+  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+    list(APPEND LIBUNWIND_COMPILE_FLAGS -UNDEBUG)
+  endif ()
+else()
+  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+    list(APPEND LIBUNWIND_COMPILE_FLAGS -DNDEBUG)
+  endif ()
+endif ()
+
+# This is the _ONLY_ place where add_definitions is called.
+if (MSVC)
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif ()
+
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_TARGET_TRIPLE
+          "-target ${LIBUNWIND_TARGET_TRIPLE}")
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_GCC_TOOLCHAIN
+          "-gcc-toolchain ${LIBUNWIND_GCC_TOOLCHAIN}")
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_SYSROOT
+          "--sysroot=${LIBUNWIND_SYSROOT}")
+
+#===============================================================================
+# Setup Source Code
+#===============================================================================
+
+include_directories(include)
+
+add_subdirectory(src)
+
diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
new file mode 100644
index 0000000..a36f978
--- /dev/null
+++ b/cmake/config-ix.cmake
@@ -0,0 +1,45 @@
+
+include(CheckCCompilerFlag)
+include(CheckCXXCompilerFlag)
+include(CheckLibraryExists)
+
+# Check compiler flags
+check_c_compiler_flag(-funwind-tables         LIBUNWIND_HAS_FUNWIND_TABLES)
+check_cxx_compiler_flag(-fPIC                 LIBUNWIND_HAS_FPIC_FLAG)
+check_cxx_compiler_flag(-fno-exceptions       LIBUNWIND_HAS_NO_EXCEPTIONS_FLAG)
+check_cxx_compiler_flag(-fno-rtti             LIBUNWIND_HAS_NO_RTTI_FLAG)
+check_cxx_compiler_flag(-fstrict-aliasing     LIBUNWIND_HAS_FSTRICT_ALIASING_FLAG)
+check_cxx_compiler_flag(-nodefaultlibs        LIBUNWIND_HAS_NODEFAULTLIBS_FLAG)
+check_cxx_compiler_flag(-nostdinc++           LIBUNWIND_HAS_NOSTDINCXX_FLAG)
+check_cxx_compiler_flag(-Wall                 LIBUNWIND_HAS_WALL_FLAG)
+check_cxx_compiler_flag(-W                    LIBUNWIND_HAS_W_FLAG)
+check_cxx_compiler_flag(-Wno-unused-function  LIBUNWIND_HAS_WNO_UNUSED_FUNCTION_FLAG)
+check_cxx_compiler_flag(-Wunused-variable     LIBUNWIND_HAS_WUNUSED_VARIABLE_FLAG)
+check_cxx_compiler_flag(-Wunused-parameter    LIBUNWIND_HAS_WUNUSED_PARAMETER_FLAG)
+check_cxx_compiler_flag(-Wstrict-aliasing     LIBUNWIND_HAS_WSTRICT_ALIASING_FLAG)
+check_cxx_compiler_flag(-Wstrict-overflow     LIBUNWIND_HAS_WSTRICT_OVERFLOW_FLAG)
+check_cxx_compiler_flag(-Wwrite-strings       LIBUNWIND_HAS_WWRITE_STRINGS_FLAG)
+check_cxx_compiler_flag(-Wchar-subscripts     LIBUNWIND_HAS_WCHAR_SUBSCRIPTS_FLAG)
+check_cxx_compiler_flag(-Wmismatched-tags     LIBUNWIND_HAS_WMISMATCHED_TAGS_FLAG)
+check_cxx_compiler_flag(-Wmissing-braces      LIBUNWIND_HAS_WMISSING_BRACES_FLAG)
+check_cxx_compiler_flag(-Wshorten-64-to-32    LIBUNWIND_HAS_WSHORTEN_64_TO_32_FLAG)
+check_cxx_compiler_flag(-Wsign-conversion     LIBUNWIND_HAS_WSIGN_CONVERSION_FLAG)
+check_cxx_compiler_flag(-Wsign-compare        LIBUNWIND_HAS_WSIGN_COMPARE_FLAG)
+check_cxx_compiler_flag(-Wshadow              LIBUNWIND_HAS_WSHADOW_FLAG)
+check_cxx_compiler_flag(-Wconversion          LIBUNWIND_HAS_WCONVERSION_FLAG)
+check_cxx_compiler_flag(-Wnewline-eof         LIBUNWIND_HAS_WNEWLINE_EOF_FLAG)
+check_cxx_compiler_flag(-Wundef               LIBUNWIND_HAS_WUNDEF_FLAG)
+check_cxx_compiler_flag(-pedantic             LIBUNWIND_HAS_PEDANTIC_FLAG)
+check_cxx_compiler_flag(-Werror               LIBUNWIND_HAS_WERROR_FLAG)
+check_cxx_compiler_flag(-Wno-error            LIBUNWIND_HAS_WNO_ERROR_FLAG)
+check_cxx_compiler_flag(/WX                   LIBUNWIND_HAS_WX_FLAG)
+check_cxx_compiler_flag(/WX-                  LIBUNWIND_HAS_NO_WX_FLAG)
+check_cxx_compiler_flag(/EHsc                 LIBUNWIND_HAS_EHSC_FLAG)
+check_cxx_compiler_flag(/EHs-                 LIBUNWIND_HAS_NO_EHS_FLAG)
+check_cxx_compiler_flag(/EHa-                 LIBUNWIND_HAS_NO_EHA_FLAG)
+check_cxx_compiler_flag(/GR-                  LIBUNWIND_HAS_NO_GR_FLAG)
+
+check_library_exists(c printf "" LIBUNWIND_HAS_C_LIB)
+check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB)
+check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB)
+
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e10ae75..c4d1fbb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -21,22 +21,21 @@ set_source_files_properties(${LIBUNWIND_ASM_SOURCES}
                               LANGUAGE C)
 
 set(LIBUNWIND_HEADERS
-  AddressSpace.hpp
-  assembly.h
-  CompactUnwinder.hpp
-  config.h
-  dwarf2.h
-  DwarfInstructions.hpp
-  DwarfParser.hpp
-  libunwind_ext.h
-  Registers.hpp
-  UnwindCursor.hpp
-  unwind_ext.h
-  ${CMAKE_CURRENT_SOURCE_DIR}/../include/libunwind.h
-  ${CMAKE_CURRENT_SOURCE_DIR}/../include/unwind.h
-)
-
-append_if(LIBCXXABI_HEADERS APPLE
+    AddressSpace.hpp
+    assembly.h
+    CompactUnwinder.hpp
+    config.h
+    dwarf2.h
+    DwarfInstructions.hpp
+    DwarfParser.hpp
+    libunwind_ext.h
+    Registers.hpp
+    UnwindCursor.hpp
+    unwind_ext.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/../include/libunwind.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/../include/unwind.h)
+
+append_if(LIBUNWIND_HEADERS APPLE
           "${CMAKE_CURRENT_SOURCE_DIR}/../include/mach-o/compact_unwind_encoding.h")
 
 if (MSVC_IDE)
@@ -54,65 +53,57 @@ if (LIBUNWIND_ENABLE_SHARED)
   add_library(unwind SHARED ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
 else()
   add_library(unwind STATIC ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
-endif()
-
-include_directories("${LIBCXXABI_LIBCXX_INCLUDES}")
+endif ()
 
 # Generate library list.
-set(libraries ${LIBCXXABI_CXX_ABI_LIBRARIES})
-append_if(libraries LIBCXXABI_HAS_C_LIB c)
-append_if(libraries LIBCXXABI_HAS_DL_LIB dl)
-append_if(libraries LIBCXXABI_HAS_PTHREAD_LIB pthread)
+set(libraries ${LIBUNWINDCXX_ABI_LIBRARIES})
+append_if(libraries LIBUNWIND_HAS_C_LIB c)
+append_if(libraries LIBUNWIND_HAS_DL_LIB dl)
+append_if(libraries LIBUNWIND_HAS_PTHREAD_LIB pthread)
 
 target_link_libraries(unwind ${libraries})
 
 # Setup flags.
-append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_HAS_FPIC_FLAG -fPIC)
-append_if(LIBCXXABI_LINK_FLAGS LIBCXXABI_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_FPIC_FLAG -fPIC)
+append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_NO_RTTI_FLAG -fno-rtti)
+
+append_if(LIBUNWIND_LINK_FLAGS LIBUNWIND_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
 
-set(LIBUNWIND_COMPILE_FLAGS)
-append_if(LIBUNWIND_COMPILE_FLAGS LIBCXXABI_HAS_NO_RTTI_FLAG -fno-rtti)
-if ( LIBCXXABI_HAS_NO_EXCEPTIONS_FLAG AND LIBCXXABI_HAS_FUNWIND_TABLES )
+if (LIBUNWIND_HAS_NO_EXCEPTIONS_FLAG AND LIBUNWIND_HAS_FUNWIND_TABLES)
   list(APPEND LIBUNWIND_COMPILE_FLAGS -fno-exceptions)
   list(APPEND LIBUNWIND_COMPILE_FLAGS -funwind-tables)
-elseif( LIBUNWIND_ENABLE_SHARED )
-  message(FATAL_ERROR "Compiler doesn't support generation of unwind tables "
-                      "if exception support is disabled.  Building libunwind "
-                      "DSO with runtime dependency on libcxxabi is not "
-                      "supported.")
+elseif (LIBUNWIND_ENABLE_SHARED)
+  message(FATAL_ERROR
+          "Compiler doesn't support generation of unwind tables if exception "
+          "support is disabled.  Building libunwind DSO with runtime dependency "
+          "on C++ ABI library is not supported.")
 endif()
 
-set(LIBCXXABI_UNWINDER_NAME "unwind")
-
-if ( APPLE )
-  if ( CMAKE_OSX_DEPLOYMENT_TARGET STREQUAL "10.6" )
-    list(APPEND LIBCXXABI_COMPILE_FLAGS "-U__STRICT_ANSI__")
-    list(APPEND LIBCXXABI_LINK_FLAGS
-      "-compatibility_version 1"
-      "-current_version ${LIBCXXABI_VERSION}"
-      "-install_name /usr/lib/lib${LIBCXXABI_UNWINDER_NAME}.1.dylib"
-      "/usr/lib/libSystem.B.dylib")
-  else()
-    list(APPEND LIBCXXABI_LINK_FLAGS
-      "-compatibility_version 1"
-      "-install_name /usr/lib/lib${LIBCXXABI_UNWINDER_NAME}.1.dylib")
-  endif()
-endif()
+if (APPLE)
+  list(APPEND LIBUNWIND_COMPILE_FLAGS "-U__STRICT_ANSI__")
+  list(APPEND LIBUNWIND_LINK_FLAGS
+       "-compatibility_version 1"
+       "-install_name /usr/lib/libunwind.1.dylib")
+
+  if (CMAKE_OSX_DEPLOYMENT_TARGET STREQUAL "10.6")
+    list(APPEND LIBUNWIND_LINK_FLAGS
+         "-current_version ${LIBUNWIND_VERSION}"
+         "/usr/lib/libSystem.B.dylib")
+  endif ()
+endif ()
 
-string(REPLACE ";" " " LIBCXXABI_COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}")
 string(REPLACE ";" " " LIBUNWIND_COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}")
-string(REPLACE ";" " " LIBCXXABI_LINK_FLAGS "${LIBCXXABI_LINK_FLAGS}")
+string(REPLACE ";" " " LIBUNWIND_LINK_FLAGS "${LIBUNWIND_LINK_FLAGS}")
 
 set_target_properties(unwind
-  PROPERTIES
-    COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS} ${LIBUNWIND_COMPILE_FLAGS}"
-    LINK_FLAGS    "${LIBCXXABI_LINK_FLAGS}"
-    OUTPUT_NAME   "${LIBCXXABI_UNWINDER_NAME}"
-    VERSION       "1.0"
-    SOVERSION     "1"
-  )
+                      PROPERTIES
+                        COMPILE_FLAGS "${CMAKE_COMPILE_FLAGS} ${LIBUNWIND_COMPILE_FLAGS}"
+                        LINK_FLAGS    "${CMAKE_LINK_FLAGS} ${LIBUNWIND_LINK_FLAGS}"
+                        OUTPUT_NAME   "unwind"
+                        VERSION       "1.0"
+                        SOVERSION     "1")
 
 install(TARGETS unwind
-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-  ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-  )
+        LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+        ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+