Warn about boolean expression compared with an integer value different from true/false
Wbuiltin-macro-redefined
-C ObjC C++ ObjC++ Warning
+C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
Warn when a built-in preprocessor macro is undefined or redefined
Wc90-c99-compat