base: support magic clang macros, cleanups
base: support magic clang macros, cleanups

ifduyue/libusual,ifduyue/libusual,mgjv/libusual,ifduyue/libusual,rabbitt/libusual,markokr/libusual,rabbitt/libusual,rabbitt/libusual,markokr/libusual,mgjv/libusual,mgjv/libusual,markokr/libusual,mgjv/libusual,markokr/libusual,rabbitt/libusual,ifduyue/libusual