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    SubjectRe: [PATCH] Protect prefetch macro arguments.
    On 03/26/2010 02:04 PM, Linus Torvalds wrote:
    >
    >
    > On Fri, 26 Mar 2010, David Daney wrote:
    >>
    >> The GCC built-in __builtin_prefetch() is a vargs function. If we
    >> don't wrap the macro parameter in parentheses, a comma operator in the
    >> actual argument list might cause unintended parameters to be passed to
    >> __builtin_prefetch().
    >
    > This seems totally pointless and actively wrong.

    Pointless, perhaps. But 'actively wrong'? Are you sure about that?

    In any event I guess I don't care much one way or the other. I was
    working on something else when I saw this. It looked wrong to me.

    Thanks,
    David Daney


    >
    > You cannot have a comma operator in the actual argument list to the
    > #define, because if you did, then you'd get a
    >
    > macro "prefetch()" passed 2 arguments, but takes just 1
    >
    > so the only way I see to pass a comma operator is to _already_ have the
    > macro parameter in parenthesis.
    >
    > Linus



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