Re: [PATCH] Documentation: Explain a second alternative for multi-linemacros.

From: Jan Engelhardt
Date: Mon Jan 01 2007 - 10:42:14 EST



On Dec 31 2006 19:23, Randy Dunlap wrote:
>> >
>> > #define setcc(cc) ({ \
>> > partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3); \
>> > partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3); })
>>
>> This _does_ return a value though, bad example.
>
> Where does it return a value? I don't see any uses of it
> in arch/i386/math-emu/* that use it as returning a value.
>
> And with a small change to put it inside a do-while block
> instead of ({ ... }), it at least builds cleanly.
> I expected some complaints.

If people want to return something from a ({ }) construct, they should do it
explicitly, e.g.

#define setcc(cc) ({ \
partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3); \
partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3); \
partial_status; \
})


-`J'
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