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

From: Randy Dunlap
Date: Sun Dec 31 2006 - 22:38:33 EST

Segher Boessenkool wrote:
In this case, the second form
should be used when the macro needs to return a value (and you can't
use an inline function for whatever reason), whereas the first form
should be used at all other times.

that's a fair point, although it's certainly not the coding style
that's in play now. for example,

#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.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at