Fix compilation on macOS without apple-clang

Signed-off-by: Steven WdV <swdv@cs.ru.nl>

Author: stevenwdv

library/CMakeLists.txt

@@ -219,11 +219,11 @@ if(WIN32)
     set(libs ${libs} ws2_32 bcrypt)
 endif(WIN32)
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-    SET(CMAKE_C_ARCHIVE_CREATE   "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
-    SET(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
-    SET(CMAKE_C_ARCHIVE_FINISH   "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")
-    SET(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")
+if(CMAKE_C_COMPILER_ID MATCHES "AppleClang")
+    set(CMAKE_C_ARCHIVE_CREATE   "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
+    set(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
+    set(CMAKE_C_ARCHIVE_FINISH   "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")
+    set(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")
 endif()
 
 if(HAIKU)