Something along these lines should work, for at least both of GCC and Clang: extern void banned() __attribute__((deprecated("This function is problematic")

Something along these lines should work, for at least both of GCC and Clang: extern void banned() __attribute__((deprecated("This function is problematic"))); #define strcpy(...) strcpy(__VA_ARGS__); banned; Which would output something along the lines of: test.c:11:3: warning: 'banned' is deprecated: This function is problematic [-Wdeprecated-declarations] strcpy(x, y);