Messages in this thread | | | Date | Wed, 21 Jan 2009 18:28:37 +0100 | From | Sam Ravnborg <> | Subject | Re: Confusion in usr/include/asm-generic/fcntl.h |
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On Wed, Jan 21, 2009 at 01:13:16PM +0100, Arnd Bergmann wrote: > On Wednesday 21 January 2009, Sam Ravnborg wrote: > > Could we add a new symbol for this? > > We know we are going to use this in several places so a simpler variant > > would be more readable. > > > > Something like: > > > > #ifdef __64BIT > > ... > > #endif > > > > When we define __64BIT we would use the __BITS_PER_LONG == 64 check. > > I would prefer using the __BITS_PER_LONG == 64 check directly, because > it gives you a warning when __BITS_PER_LONG is undefined, whereas the > #ifdef check gets easily fooled by include order problems. Note that > this is not a problem in the kernel for CONFIG_* symbols which are > always defined before the first #include.
It gives the warning only if you add -Wundef which IIRC is not default with -Wall. And using the "__BITS_PER_LONG == 64" the risk of gitting the expression wrong is much higher than the simpler variant where you only write:
__64BIT
But I have no strong feelings for it.
Sam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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