qt5base-lts/mkspecs/features/uikit/bitcode.prf

!versionAtLeast(QMAKE_XCODE_VERSION, 7.0) {
    warning("You need to update Xcode to version 7 or newer to support bitcode")
} else: !macx-xcode {
    # Simulator builds and all debug builds SHOULD use -fembed-bitcode-marker,
    # but unfortunately the -fembed-bitcode and -fembed-bitcode-marker driver
    # flags do not work in conjunction with -Xarch, so we'll have to let it use
    # the "wrong" flags for now (note that this issue affects only the Makefile
    # generator). We also don't want the flags to be passed in Xcode builds, as
    # the Xcode ENABLE_BITCODE setting will take care of that for us.
    release {
        QMAKE_CFLAGS           += -fembed-bitcode
        QMAKE_CXXFLAGS         += -fembed-bitcode
        QMAKE_OBJECTIVE_CFLAGS += -fembed-bitcode
        QMAKE_LFLAGS           += -fembed-bitcode
    } else {
        QMAKE_CFLAGS           += -fembed-bitcode-marker
        QMAKE_CXXFLAGS         += -fembed-bitcode-marker
        QMAKE_OBJECTIVE_CFLAGS += -fembed-bitcode-marker
        QMAKE_LFLAGS           += -fembed-bitcode-marker
    }
}