Re: [PATCH] string.h, _BSD_SOURCE, and *index()

[Rich Felker <dalias@aerifal.cx>]

On Fri, Apr 13, 2012 at 01:52:27PM +1200, Andre Renaud wrote:
> On Fri, Apr 13, 2012 at 1:45 PM, Isaac Dunham <idunham@lavabit.com> wrote:
> > (r)index was X/Open legacy, and has been dropped. The Open Group
> > recommended using
> > #define index(a,b) strchr((a),(b))
> > #define rindex(a,b) strrchr((a),(b))
> > Which will let us remove two more files if we do it (rindex.c & index.c)
> > However, would removing those break the ABI?
> 
> I'm curious about this - what is the general consensus on using
> #define to do these kind of translations, versus using static inline
> functions, such as:
> static inline char *index(const char *s, int c) {return strchr(s, c);}
> static inline char *rindex(const char *s, int c) {return strrchr(s, c);}

Both are wrong to do in this header, but the static inline definition
is even "more wrong". Non-static inline would be okay, but static
inline conflicts with the "correct" (albeit removed) declaration of
the function and will actively break code that prototypes the
function (and can't be removed with #undef).

Rich