Re: [Qemu-devel] [PATCH 1/5] CODING_STYLE: add preprocessor rules

[Andreas Färber]

Am 13.08.2010 um 18:56 schrieb Blue Swirl:

> > > +Use parenthesis when checking if a macro is defined, and use
> > > +indentation to track nesting:
> > > +
> > > +#if defined(HAVE_POSIX_FALLOCATE) && !defined(HAVE_FALLOCATE)
> > > +# define fallocate(a,ignored,b,c) posix_fallocate(a,b,c)
> > > +#endif
>
> This one is new, current code doesn't use indentation. Maybe it's
> better to drop it.

Yes, please. While indentation is nice to read, it is patch-unfriendly.

Consider:

#ifdef SOMETHINGNEW
yay
#else // previous stuff follows

#if defined(OLDONE)
#  define one
#endif
foo
bar
#if defined(OLDTWO)
#  define two
#endif

#endif

Here, adding four lines would require to reindent six lines otherwise  
not changed, making merging and review harder.

Andreas