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

From: Segher Boessenkool
Date: Sun Dec 31 2006 - 23:33:12 EST

#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?

partial_status |=

I don't see any uses of it

Ah, that's a separate thing -- it returns a value, it's just
never used.

And with a small change to put it inside a do-while block
instead of ({ ... }), it at least builds cleanly.

Well please replace it then, statement expressions should be
avoided where possible (to start with, they don't have well-
defined semantics).


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