• Steven Rostedt's avatar
    WARN_ON_SMP(): Add comment to explain ({0;}) · ccd0d44f
    Steven Rostedt authored
    The define to use ({0;}) for the !CONFIG_SMP case of WARN_ON_SMP()
    can be confusing. As the WARN_ON_SMP() needs to be a nop when
    CONFIG_SMP is not set, including all its parameters must not be
    evaluated, and that it must work as both a stand alone statement
    and inside an if condition, we define it to a funky ({0;}).
    
    A simple "0" will not work as it causes gcc to give the warning that
    the statement has no effect.
    
    As this strange definition has raised a few eyebrows from some
    major kernel developers, it is wise to document why we create such
    a work of art.
    
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Alexey Dobriyan <adobriyan@gmail.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    ccd0d44f
bug.h 5.53 KB