build: use POSITION_INDEPENDENT_CODE instead of -fPIC

Rather than hardcode the flag and check if the compiler supports it, use
the CMake property to get the right flag spelling for the compiler.
This makes it generally more portable.

llvm-svn: 314834

diff --git a/libunwind/cmake/config-ix.cmake b/libunwind/cmake/config-ix.cmake
index e2041af..2d4da64 100644 (file)
--- a/libunwind/cmake/config-ix.cmake
+++ b/libunwind/cmake/config-ix.cmake
@@ -52,7 +52,6 @@ endif ()
 
 # 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)

diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
index 0b2a7c9..d165958 100644 (file)
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -57,7 +57,6 @@ if (LIBUNWIND_ENABLE_THREADS)
 endif()
 
 # Setup flags.
-append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_FPIC_FLAG -fPIC)
 append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_NO_RTTI_FLAG -fno-rtti)
 
 append_if(LIBUNWIND_LINK_FLAGS LIBUNWIND_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
@@ -100,7 +99,8 @@ add_library(unwind_objects OBJECT ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
 
 set_target_properties(unwind_objects
                       PROPERTIES
-                        COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}")
+                        COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}"
+                        POSITION_INDEPENDENT_CODE ON)
 
 set(LIBUNWIND_TARGETS)