compat FEATURE use standalone compat "library"
diff --git a/CMakeModules/UseCompat.cmake b/CMakeModules/UseCompat.cmake
new file mode 100644
index 0000000..bac4027
--- /dev/null
+++ b/CMakeModules/UseCompat.cmake
@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 2.8.12)
+
+include(CheckSymbolExists)
+include(TestBigEndian)
+
+macro(USE_COMPAT)
+ # compatibility checks
+ set(CMAKE_REQUIRED_DEFINITIONS -D_POSIX_C_SOURCE=200809L)
+ list(APPEND CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
+ list(APPEND CMAKE_REQUIRED_DEFINITIONS -D__BSD_VISIBLE=1)
+ check_symbol_exists(vdprintf "stdio.h;stdarg.h" HAVE_VDPRINTF)
+ check_symbol_exists(asprintf "stdio.h" HAVE_ASPRINTF)
+ check_symbol_exists(vasprintf "stdio.h" HAVE_VASPRINTF)
+
+ check_symbol_exists(strndup "string.h" HAVE_STRNDUP)
+ check_symbol_exists(strnstr "string.h" HAVE_STRNSTR)
+ check_symbol_exists(getline "stdio.h" HAVE_GETLINE)
+
+ check_symbol_exists(get_current_dir_name "unistd.h" HAVE_GET_CURRENT_DIR_NAME)
+
+ TEST_BIG_ENDIAN(IS_BIG_ENDIAN)
+
+ # header and object file
+ configure_file(${PROJECT_SOURCE_DIR}/compat/compat.h.in ${PROJECT_BINARY_DIR}/compat.h @ONLY)
+ include_directories(${PROJECT_BINARY_DIR})
+ add_library(compat OBJECT ${PROJECT_SOURCE_DIR}/compat/compat.c)
+ set_property(TARGET compat PROPERTY POSITION_INDEPENDENT_CODE ON)
+endmacro()