Use -D_FORTIFY_SOURCE instead of -Wp,-D_FORTIFY_SOURCE.
Do not use -Wp as one can't then easily overwrite the macro with: -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3.
Do not use -Wp as one can't then easily overwrite the macro with: -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3.